My Delta to Tjunction at load is about 25 Degrees, with it being 50 Degrees at idle.
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My Delta to Tjunction at load is about 25 Degrees, with it being 50 Degrees at idle.
Here's a guy on the [H] forum that decided to take my test using his E6400 revision L2.
http://www.hardforum.com/showpost.ph...3&postcount=87
Though his heatsink and fan are far superior at cooling then my OEM heatsink and fan, he ended up with the exact same results.
His absolute core temperature with an assumed Tjunction of 85C was equal to his ambient temperature.
The assumed Tjunction of 100C that CoreTemp 0.95 uses for his L2 E6400 processor doesn't seem right. That's all I'm really trying to prove.
joebuffalo: "You assume that the air inside your case is the same temperature as the air outside the case.
No I didn't. The case was open and the temperature probe was beside the cpu fan.
"You are assuming that Tjmax is either 85 or 100.""
The Core2Duo mobile processors with the exact same CPUID of 6F6 have a documented TjMax of a fixed 100C or 85C. Why would Intel change their manufacturing process for the Core2 Duo desktop processors that have the same 6F6 CPUID? They're the same processor built on the same manufacturing process. The only difference is the packaging they're shoved into with a different pin count for a mobile or desktop application.
Assuming TjMax isn't a fixed value of 85C or 100C is no different than assuming it is a fixed value. Until documentation is released by Intel to clarify this, neither side can be proven to be right or wrong.
Try taking my Tjunction test and let's see what kind of results you get. I'm very interested in results from E4300 users.
No offense, unlcewebb, but not only will I not take your test, I will advise others against taking your test. It confuses the matter (for those that don't understand Core2 temperature readings) and serves no purpose (for those that do understand Core2 temperatures).
The only thing anybody with a Core2 Duo desktop processor should do is read their DTS directly from CoreTemp 0.95
Quote:
Originally Posted by SLi_dog
Actually, it makes *perfect* sense:
The software reads the DTS directly from the CPU as '55'
The software *assumes* a tjmax of '100'
The software *calculates* a core temperature of '45'
Why not just use the ''clasic'' diode from PECI ?...
Mine results with an 6400 at 3600@ 1.417v watercooled 24C room 26-27C Radiators(3x dual nexXxos) are...
idle core temp 39-41c (ok i will tell the max of one core only)
idle PECI from AI SUITE 32-33
Full load orthos after 30s
Full core temp : 65c
Full PECI AI SUITE 55C
After some tests i realize that core temp was WRONG.It says 10C More under load and 7-8C on idle.
In my opinion if all previous posts are right them...coretemp is just for some cores/cpus.
One reason you won’t be able to rely on the PECI reading of the on die thermal diode is that Intel has discontinued or disabled the Diode on newer CD2 processors and only the DTS is used for thermal management and fan control...Quote:
Originally Posted by cmos.gr
Perhaps better support is inevitable for developers of software monitoring core temperature.
Every processor package varies slightly and T-junction being set per package during manufacturing and not software readable makes this a chore to determine the actual thermal design limit.
If you run Ortho’s for any length of time at max load you will notice the margin of error is less from core temp to the diode reading and this varies from build to build.
For now that’s what we have and it is not perfect
In some cases just wrong.
I rely on the motherboard software more than Core temp because of the discrepancies.
If it’s stable why worry.:cool:
uhm so...
If someone want to see if his core temp or any prog reports right temperature the only thing he has to do is to stop his cooler's fan or pump for watercool and see if at 85 (reported) temp his CPU will start throttling..
If yes then temp progs like core temp are fine.
Right ?
Edit:
I just test mine and...
At reported temp of 83C° (core temp) cpuz gone from 2128mhz to 1600mhz (default 6400 to make sure TM is working fine)
Now what ? The right temp is not only higher (than PECI) but +2C° more than core temp's reported temperature ?
Sh..t thats TOO bad uh ? :S :S :S
In theory Yes.
If your a brave soul:)
Lol thats not a prob..ill not cry for them :P
Ok so test # 2 (from a guy at hard forums)
266fsb*6multi@ 1.07vcore.
Radiator Temperature 25C (+-1 or 2 cause its from a gatewatch panel...(i need to find fast a good tool for temp)
IDLE
Motherboard temp(or peci I really don't know wtf is that temp) : 24C (impossible ?! but NEAR radiator temperature)
Core 1 :31C
Core 2 :30C
Its +- 5C° more than radiator temperature.
I cant believe this can be right with these settings.Only 1600mhz and 1.07vcore IDLE...
Argh I'm confused:confused:
Or finaly I must say to my self that I have a really hot chip.what can I say :S
Those temps seem to be in line considering the applied voltage.
As for core temp TAT or speed fans functionality I’ll do a quick comparison between platforms.
My core duo lap top with TAT or Orthos running full load and no overclock the temperature reported by TAT and core temp never exceed 47C .
This is in a little flat black box with virtually no air flow and a heat pipe with a fan on the end exhausting out the back..
Using TAT and core temp in my desktop with excellent air flow and high a high end liquid cooling solution the temperatures will soar upward of 60C(TAT) 51C orthos.
This could be the fact that TAT was designed for the mobile platform and similarly core temp seems to be more accurate at low applied voltages or higher clocks at max load.
The discrepancy I have noted is in the area where Fan speed control is commanded or TCC activation.
Is core Temp accurate?
In many cases yes.
Then again Intel states that the Bios or Intel interrogator software is accurate within 3C.
Some how I believe in the very near future you will see Core temp to be very reliable but at this time there is no 100% accurate temperature reporting utility.
Like I said before
If its stable why worry.
That was a nice example...
Only a word on this
If it was stable at your temp ( 51C orthos )I wont say anything...:(Quote:
If its stable why worry.
But here I see a 8-10C difference between 3 Sensors (numbers lets say better).
Please if anyone can to this test...post his results.:toast:
Post the CPU , Core 0 and Core 1 idle from SpeedFan 4.32
Then
Enable PECI from bios and post the same temps Cpu, core 0 and core 1.
I test that in 2 systems with same mobo different cpus and i got different results.:confused:
On my system CPU temp (peci anyway) had +-10 temp less than core 0-1
On other system CPU temp was exactly the same with core 0-1.:stick:
And one more thing.
Tjunction is at 85C ?Thats a standard ? 100% ?
Lets say...it cant be at 80 ? so coretemp or any program uses DTS report wrong temp ?Cause mine for example was not as 85 but in 83 (IF temp was right then why Tjunction enabled at 83 and not at 85 for my cpu?...:rolleyes: )
I'm really stuck on that now :dammit:
Here are the things we know 100% for certain regarding Core2 Temperatures:
1. Nobody knows for sure what the Tjmax is for a Core2 Desktop Processor
2. DTS readings are always 99% percent accurate and should not be questioned
3. CoreTemp 0.95 can be configured to display DTS readings directly
4. Absolute temperatures are unnecessary and confusing. Learn to embrace DTS.
So why I have still 2-3 C to Tjunction but CPU started already?Quote:
2. DTS readings are always 99% percent accurate and should not be questioned
Who says that the real Tjuncton isn't at 75C ?(at this temp +- (i don't remember for sure)reported from Tcase diode.)
CoreTemp still calculates with report point 85C which isn't the real Tjunction.
And if..
DTS readings (from CoreTemp)in my case are wrong.Quote:
3. CoreTemp 0.95 can be configured to display DTS readings directly
I tested.:nono:
Its just the reverse:nono:
first of all, on desktop and server processors the reference point used is not tjunction but tcc (thermal control circuit) activation temperature instead! tjunction is used on mobile processors only.Quote:
Originally Posted by cmos.gr
i know coretemp is calling this reference temperature tjunction on all processors. tat does the same, but as tat is designed for mobile processors only it is naming this reference temperature correct. guess thats the reason many people call this reference point tjcunction.
anyway, this does not change anything in the resulting temperatures ...
so why have you seen throttling starting at a coretemp reading of 83C? coretemp uses a sample rate of 1 second by default. the last time coretemp read the dts value coretemp might have read 2C and thus calculated 83C absolute temperature, but as dts and tcc reacts very fast it started throttling even before coretemp was able to read the next dts value a second later.
you can try to set the temperature read interval in coretemp to a lower value and you might see different temperatures where throttling starts.
besides that, the temperature where tcc gets activated is calibrated during manufacturing on a per part basis and thus might differ from processor to processor. regardless of coretemp, which will read anything near 85C or near 100C (depending on the assumed reference temperature), your processor might start throttling at 83C, 84C or even 87C. you simply cant tell, cause its impossible to convert dts readings into an absolute temperature.
thats the reason i requested the display of plain dts values through coretemp. which was implemented in coretemp095. instead of trying to keep your processor below a certain temperature you should try to keep dts readings ABOVE a certain value which means staying away from tcc activation by this value.
there is no tcase diode in c2d processors! the td (thermal diode) you are referring is like the dts (digital thermal sensor) located on the die itself and thus reports processor temperature directly from the die. the dts has a smaller foot print than the td and thus can be located closer to hotspots on the die. also dts reacts very fast and dts temperatures can be read directly as a 7bit value from a register. in contrast td needs two pins on the processor socket where an electric signal can be measured which needs to be calibrated and converted into a temperature! thus accuracy of temperature readings via td rely on calibration ond conversion. as this is done in bios, its up to the bios what temperatures are read via td. the bios might calibrate this temp to simulate a temperature similar to tcase definitions by intel or it might be calibrated to simulate a temperature which is close to core temperatures. you simply don't know what the bios writer had in mind.Quote:
Who says that the real Tjuncton isn't at 75C ?(at this temp +- (i don't remember for sure)reported from Tcase diode.)
regarding tcase:
intel defines tcase as the temperature measured at the geometric center of the ihs on top of the ihs surface! there is no temperature sensor nor a diode reporting this temperatur. it's just a place outside the processor where temperatures may be measured ...
as dts temperatures are an offset to tcc activation, coretemp as all other software using dts has to calculate absolute temperatures by subtracting dts readings from tcc activation temperature. the problem here is this tcc activation temperature, as mentioned above, is different from part to part and once configured during manufacturing can't be changed nor read out by any software! this tcc activation temperature simply has to be assumed somehow!Quote:
CoreTemp still calculates with report point 85C which isn't the real Tjunction.
And if..
DTS readings (from CoreTemp)in my case are wrong.
I tested.:nono:
Its just the reverse:nono:
on mobile processors a bit in a register exists which tells if tjunction (which is used on mobile processors only) is at 85C or at 100C.
this bit is NOT valid on desktop and server processors. depending on the content of this single bit, temp monitoring software assumes if 85C or 100C has to be used in subsequent calculations. this assumption might be close to reality on many processors, but definitely is about 15C off on some other processors.
yes, DTS readings are correct! the problem is in the conversion into absolute temperature values as explained above. here comes inaccuracy into play ...Quote:
DTS readings are always 99% percent accurate and should not be questioned
I originally thought that this was the case as well but according to the creator of CoreTemp, the configured "Delta to Tjunction" temperature are direct DTS readings only, no calculation is involved.Quote:
Originally Posted by cmos.gr
Seems you were right Joe :toast:Quote:
Originally Posted by joebuffalo
I think what cmos.gr has noticed is that processor throttling begins at a CoreTemp 0.95 DTS value of 2.Quote:
Originally Posted by fgw
By controlling the cpu fan speed I can bring the temperature up very gradually and TAT will first report "Thermal Monitor Active" in red when DTS=2. RightMark also reports at this point "CPU core overheat detected" and shows that some form of throttling is taking place.
By adjusting the fan speed I can hold DTS=2 without letting it ever get to zero. If I turn up the fan speed a little to cool things down, as soon as CoreTemp reports DTS=3, the TAT Thermal Monitor Active light turns back to green and changes to Thermal Monitor Idle.
This testing seems to show that processing power first gets reduced at DTS=2. I don't think the TAT reported MHz gets reduced until DTS=0 but that doesn't mean that the processor isn't already throttling.
http://img209.imageshack.us/img209/2...testingep4.png
Note: Just to clear things up. I booted up at 425 X 8 = 3400 MHz and then used ClockGen to reduce it to 400 X 8 = 3200 MHz for better stability at full load and full temp before starting this test. CoreTemp reports the wrong MHz but the 3200 MHz in TAT is correct. This first level of throttling does not reduce the reported 3200 MHz the processor was originally running at.
On a side note, does anyone know why TAT grays out CPU1 sometimes as in the above picture?
Actually my cpu reduced mhz at DTS = 2
I think your setup/configure is not able to slow down your processor...
This happen to me..Only with default setting it could slow down cpu speed.
I did another test and this time I let the temperature go higher until DTS=0.
TAT held steady at 3200 MHz but CPUz showed it being reduced to 3167 MHz and once it dropped down to the low 2000 MHz range but I missed a screenshot of that.
CoreTemp showed that the VID had been reduced from 1.325 to 1.1625 volts. SpeedFan and CPUz showed the core voltage steady at 1.392 volts so the Asus P5B might lock the CPU voltage and ignore any requests to lower it when it is not set to AUTO in the bios.
TAT and SpeedFan occasionally reported absolute temps of -40C to -42C when the temps seemed to go higher.
http://img235.imageshack.us/img235/6...esting2jq3.png
Wow, now that's a hot processor!
This is interesting work you are doing and I it will surely help us to better understand the Core2 Desktop processors. I would point out though that these new observations should not be misconstrued as evidence that the DTS reading is innaccurate. I made notes before of when other people who ran their processors to crazy high temps like you. I'll see if I can find those so we can do some comparisons.
Do you have both TM1 and TM2 enabled in your BIOS (or maybe they are disabled in some software - I do know I've seen check-boxes for these in RightMark)? That could possibly affect what happens as you approach DTS=0.
Here is one link where sombody else saw throttling at DTS=2:
http://forumz.tomshardware.com/hardw...588903#1588903
I had not seen this doc before (though you posted the link a long time ago) so I thank you for that unclewebb.
http://www.intel.com/design/processo...als/253668.pdf
Reading this document makes it clear that if we have a clever programmer and an intrepid tester, we can learn a lot about how this stuff is working. That MSR contains a lot of info: has thermal monitoring taken place recently? the ability to enable thermal throttling via software, etc. Very interesting.
I had mentioned a few days (weeks?) back that I thought that the Tj_max was *individually* set for *each* processor. If that were the case, we can all agree that absolute temperature are ABSOLUTELY POINTLESS, right? If you have no clue what Tj_max is, you can never accurately convert a DTS reading into an absolute temperature. NEVER. Do we agree?
Good. Now read this. I can't believe I read this like a month ago and totally forgot about it. I should have shared this with more people. It's a MUST READ for those who want to understand Core2 temperatures.
http://documents.irevues.inist.fr/bi...79/1/TMI23.pdf
Allow me to quote my two favorite lines:
"To achieve measurement accuracy, each sensor is calibrated at test time. Calibration is done for the Maximum Tj and the linearity of the readout slope. The temperature reading is post processed for filtering out random noise and generating the H/W activated thermal protection functions."
and
"The DTS is calibrated at manufacturing conditions and the reference point is set to this test temperature. Functionality, electrical specifications and reliability commitments are guaranteed at maximum Tj as measured by the DTS. Any test inaccuracy or parameters variance are already accounted for in the DTS set point"
Allow me to summarize: Absolute temperture *calculations* on Core2 processors are *pointless*. DTS *readings* are accurate and factory calibrated.
Embrace DTS. ;)
While I'm at it I might as well link to everything else useful I've collected on this topic:
http://www.intel.com/design/core2duo/documentation.htm
http://www.intel.com/technology/itj/...sign_point.htm
http://www.intel.com/technology/itj/...management.htm
ftp://download.intel.com/design/inta...d/31527902.pdf
Intel® CoreTM 2 Duo E6400 and E4300 Processors for Embedded Applications
4.2.10 Digital Thermal Sensor
The Intel® Core™2 Duo desktop processor E6000 sequence introduces the Digital
Thermal Sensor (DTS) as the on-die sensor to use for fan speed control (FSC). The DTS
will eventually replace the on-die thermal diode used in pervious products. The
processor will have both the DTS and thermal diode enabled. The DTS is monitoring the
same sensor that activates the TCC (Refer to Section 4.2.2). Readings from the DTS
are relative to the activation of the TCC. The DTS value where TCC activation occurs is
0 (zero).
The DTS can be accessed by two methods. The first is via a MSR. The value read via the
MSR is an unsigned number of degrees C away from TCC activation. The second
method which is expected to be the primary method for FSC is via the PECI interface.
The value of the DTS when read via the PECI interface is always negative and again is
degrees C away from TCC activation.
4.2.2 Thermal Control Circuit
The Thermal Control Circuit portion of the Thermal Monitor must be enabled for the
processor to operate within specifications. The Thermal Monitor's TCC, when active, will
attempt to lower the processor temperature by reducing the processor power
consumption. In the original implementation of thermal monitor this is done by
changing the duty cycle of the internal processor clocks, resulting in a lower effective
frequency. When active, the TCC turns the processor clocks off and then back on with a
predetermined duty cycle. The duty cycle is processor specific, and is fixed for a
particular processor. The maximum time period the clocks are disabled is ~3 µs. This
time period is frequency dependent and higher frequency processors will disable the
internal clocks for a shorter time period. Figure 7 illustrates the relationship between
the internal processor clocks and PROCHOT#.
Performance counter registers, status bits in model specific registers (MSRs), and the
PROCHOT# output pin are available to monitor the Thermal Monitor behavior.
4.2.3 Thermal Monitor 2
The processor supports an enhanced Thermal Control Circuit. In conjunction with the
existing Thermal Monitor logic, this capability is known as Thermal Monitor 2. This
enhanced TCC provides an efficient means of reducing the power consumption within
the processor and limiting the processor temperature.
When Thermal Monitor 2 is enabled, and a high temperature situation is detected, the
enhanced TCC will be activated. The enhanced TCC causes the processor to adjust its
operating frequency (by dropping the bus-to-core multiplier to its minimum available
value) and input voltage identification (VID) value. This combination of reduced
frequency and VID results in a reduction in processor power consumption.
ftp://download.intel.com/design/proc...s/31327803.pdf
Intel® Core2 Extreme Processor X6800 and Intel® Core2 Duo Desktop Processor E6000 and E4000 Sequences
5.1.1 Thermal Specifications
5.2.4 PROCHOT# Signal
An external signal, PROCHOT# (processor hot), is asserted when the processor core
temperature has reached its maximum operating temperature. If the Thermal Monitor
is enabled (note that the Thermal Monitor must be enabled for the processor to be
operating within specification), the TCC will be active when PROCHOT# is asserted. The
processor can be configured to generate an interrupt upon the assertion or deassertion
of PROCHOT#.
As an output, PROCHOT# (Processor Hot) will go active when the processor
temperature monitoring sensor detects that one or both cores has reached its
maximum safe operating temperature. This indicates that the processor Thermal
Control Circuit (TCC) has been activated, if enabled. As an input, assertion of
PROCHOT# by the system will activate the TCC, if enabled, for both cores. The TCC will
remain active until the system de-asserts PROCHOT#.
5.2.5 THERMTRIP# Signal
Regardless of whether or not Thermal Monitor or Thermal Monitor 2 is enabled, in the
event of a catastrophic cooling failure, the processor will automatically shut down when
the silicon has reached an elevated temperature (refer to the THERMTRIP# definition in
Table 26). At this point, the FSB signal THERMTRIP# will go active and stay active as
described in Table 26. THERMTRIP# activation is independent of processor activity and
does not generate any bus cycles.
Tabel 26
THERMTRIP#
In the event of a catastrophic cooling failure, the processor will
automatically shut down when the silicon has reached a
temperature approximately 20 °C above the maximum TC.
Assertion of THERMTRIP# (Thermal Trip) indicates the processor
junction temperature has reached a level beyond where permanent
silicon damage may occur. Upon assertion of THERMTRIP#, the
processor will shut off its internal clocks (thus, halting program
execution) in an attempt to reduce the processor junction
temperature. To protect the processor, its core voltage (VCC) must
be removed following the assertion of THERMTRIP#. Driving of the
THERMTRIP# signal is enabled within 10 µs of the assertion of
PWRGOOD (provided VTT and VCC are valid) and is disabled on deassertion
of PWRGOOD (if VTT or VCC are not valid, THERMTRIP#
may also be disabled). Once activated, THERMTRIP# remains
latched until PWRGOOD, VTT, or VCC is de-asserted. While the deassertion
of the PWRGOOD, VTT, or VCC will de-assert THERMTRIP#,
if the processor’s junction temperature remains at or above the trip
level, THERMTRIP# will again be asserted within 10 µs of the
assertion of PWRGOOD (provided VTT and VCC are valid).
5.3 Thermal Diode
The processor incorporates an on-die PNP transistor where the base emitter junction is
used as a thermal "diode", with its collector shorted to ground. A thermal sensor
located on the system board may monitor the die temperature of the processor for
thermal management and fan speed control. Table 31,Table 32, and Table 33 provide
the "diode" parameter and interface specifications. Two different sets of "diode"
parameters are listed in Table 31 and Table 32. The Diode Model parameters (Table 31)
apply to traditional thermal sensors that use the Diode Equation to determine the
processor temperature. Transistor Model parameters (Table 32) have been added to
support thermal sensors that use the transistor equation method. The Transistor Model
may provide more accurate temperature measurements when the diode ideality factor
is closer to the maximum or minimum limits. This thermal "diode" is separate from the
Thermal Monitor's thermal sensor and cannot be used to predict the behavior of the
Thermal Monitor.
http://download.intel.com/design/pro...x/31368502.pdf
Intel® Core™2 Duo Desktop Processor E6000? and E4000? Sequence Thermal and Mechanical Design Guidelines
4.2.10 Digital Thermal Sensor
The Intel® Core™2 Duo desktop processor E6000/E4000 sequence introduces the
Digital Thermal Sensor (DTS) as the on-die sensor to use for fan speed control (FSC).
The DTS will eventually replace the on-die thermal diode used in pervious products.
The processor will have both the DTS and thermal diode enabled. The DTS is
monitoring the same sensor that activates the TCC (see Section 4.2.2). Readings from
the DTS are relative to the activation of the TCC. The DTS value where TCC activation
occurs is 0 (zero).
The DTS can be accessed by two methods. The first is via a MSR. The value read via
the MSR is an unsigned number of degrees C away from TCC activation. The second
method which is expected to be the primary method for FSC is via the PECI interface.
The value of the DTS when read via the PECI interface is always negative and again is
degrees C away from TCC activation.
OK, I was re-reading the info in the above post. Important line to read: "The DTS value where TCC activation occurs is 0 (zero)."
So...When someone see DTS=0 that doesn't mean his cpu is at 85C.
He may have 60C...or 70C or 80C or 90C.
Right ?
That is the gist of it.Quote:
Originally Posted by cmos.gr
joebuffalo: Thermal Monitoring is enabled in my bios and Rightmark shows that both TM1 and TM2 are enabled.
Here's some more high temp experimenting:
http://img238.imageshack.us/img238/9...esting4ht3.png
What I found interesting today is that once again TAT went red and showed Thermal Monitor Active when CoreTemp got up to DTS=2 but TAT never reported more than 79C to 80C even as I held it at the boiling point for several minutes.
Here's a partial look at the TAT log:
http://img67.imageshack.us/img67/1011/temploguu3.gif
The other day a CoreTemp reading of DTS=2 was getting me TAT reported temps of 83C and today only 80C for the exact same DTS value. There doesn't seem to be too much logic when a computer program varies its output depending on the day of the week or who knows what.
From my experience, TAT tends to read a degree or two below CoreTemp
In the last screen shot you posted (previous page) you had TAT=83 when DTS=0
I find it odd that my first screen shot on the previous page, TAT + DTS = 85 and then on the second screen shot TAT + DTS = 83 and now this last screen shot TAT + DTS = 82.
If TAT is using the same DTS value that every other program is using then on the same computer, it should be consistent from day to day but it's not.
I can understand when there are timing differences when a sensor is read but in each case I tried to stabilize the temps before going for a screen shot.
Some people trust TAT because it has the nice Intel logo on it but I find that CoreTemp is a lot more consistent.
Agreed. Reason I don't like TAT (for reading temp) is because it will not display DTS directly and we do not know how it using DTS to calculate the absolute temperature. Two unknowns :(
I'd like to bump this very informative thread :)
This is probably the best thread on desktop core 2 duo temperatures on the web. I spent a week trying to find out why my temps were reading 15 degrees one way or the other depending on the program. My search led me to the intel forums, product documentation, and to the "temperature guide" from that other forum, Im sure you know the one.
I added up all of the facts and compared them to what was being said and I realized that most of the info on the web about reading core2duo temps is misinformation. I finally concluded that there is NO way to get an absolute temp on these desktop chips, but I also realized that this is ok because one can accurately utilize DTS and temp readings on former chips probably were not that accurate anyway. DTS is act ually a great thing.
IT was at this point that I googled DTS and C2D chips and found this thread. It was refreshing to see you guys coming down to the very same conclucion...you are right on....everyone needs to embrace DTS!
a few more things that I think need to be restated due to all the misinformation, please correct me if I am wrong:
1. TAT is NOT intended to be used with desktop C2D processors and WILL NOT give you accurate temps because temps for desktop c2d cannot be known. Mobile c2d's have a set tjunction and TAT works fine for them.
2. The word "Tjunction" itself only applies to mobile c2d's.
3. The whole reason programs are giving the 15 degree variance is because they are assuming tjunctions of 85 or 100...refer to number 2--->tjunction DOES NOT apply to desktop c2d's.
4. I am not sure about this but I think tjunction DOES apply to quads---> correct me if Im wrong. If it does and if they are documented at 100 TAT would work just fine I would assume.
5. It seems that the consensus is that DTS readings, which can be obtained from the newest coretemp are safe if above 20 or so, generally speaking.
6. Coretemp confuses the issue with its even mentioning "tjunction", this word and its use needs to be deleted from the entire program and the program should only read DTS. Even when you set it to read dts it states x dts to tjunction....this should instead read so x dts to TCC. TCC is the trip noted in the intel documents.
7. Changing the tjunction in coretemp should not affect the DTS, it looks like it would and for this reason the program is confusing to mnay...so remember DTS is not a calculated number, it is simply a readout of what the diods are reporting.
Please correct me where I went wrong, but from the forums around town it seems like there still is A LOT of confusion over this.
This thread is awesome. I have embraced DTS. :D
I finally bought an IR Thermometer to do some testing with. I've posted some interesting information over on the [H]ard forum but unfortunately the site is down at the moment.
I have an early revision B2 E6400 which every program including TAT assumes a TjMax of 85C. Using my method of lowering the core voltage and lowering the MHz as low as they go I was able to remove the fan off of the OEM heatsink and get a very accurate temperature reading directly off the copper cone in the center of the heatsink. With CoreTemp reporting 21C, the measured temperature of the heatsink was 27C.
This of course is impossible. A heat source at 21C can't possibly heat up the heatsink to 27C. After this test and others I seriously doubt if there are any C2D processors with a TjMax of 85C. All mobile Core processors, Solo, Duo, Core 2 Duo, all have an Intel documented TjMax of 100C. I continue to believe that the Desktop Core processors also use the exact same TjMax of 100C.
DTS is still the best way to go but for those that are interested in an absolute temperature, I would only use software that assumes a TjMax = 100C.
Next step is to try and run the processor without a heatsink with only a highspeed 80mm hand held fan keeping it cool. If it's possible to run a C2D like this without the core temps going through the roof then I will be able to get a direct temp reading of the cores without a heatsink getting in the way, reducing the true core temperature.
Should have some interesting results by next week if nothing catches on fire!
Curious about your findings unclewebb :)
Me also having problems with the understanding of my own E6600 temps.
Hardware :
- E6600
- Asus P5B-e
- Asus 8800 GTS 320 mb
- Antec NSK6000 (front 2x 92 mm fans, bottom 120 mm intake fan @ 800 rpm and back outtake 120 mm AC fan).
Temps are :
Ambient 21.3 celcius
- IDLE
CPU : 42
Motherboard : 40
Core 0 : 23
Core 1 : 23
(on the screenshots after a cold boot)
- STRESSED
CPU : 56
Motherboard : 41
Core 0 : 41
Core 1 : 41
As you can see the CPU temp is higher then Core temp.
Are those Core temps realistic with this Ambient temperature?.
I started a thread on Tom's Hardware asking about this and some of their members say that CPU temp is way to high (55 is max for Orthos) as I have +/-56).
Quote from another member @ Tom's Hardware
As you can see and already sayed in this thread, it's get a bit (alot) confusing :)Quote:
Dude, the CPU temp of 56-60 is what is reading accurately, your two core temps are the ones which are inaccurate and need to be offset. Read the C2D temp guide. By the way, your accurate cpu temp of 56 is too high, the guide explains that you should never exceed 55 with orthos, 60 with TAT.
..
What that means is your actually loading @56/71-71 <---> 60/75-75 which is too high. Stay bellow 55/70-70 using Orthos.
For @56/44-44 to be accurate or what ever, that would mean you are water cooled. By deductive logic, the 44s are then the ones reading inaccurately. 44 Tjunction doesnt make sense on Orthos unless you are watercooling, meaning it definately needs to be offset by +~27. I had to offset mine by +~25. Same boat as you.
-- Screenshots --
http://img108.imagevenue.com/loc1146...122_1146lo.jpg - http://img41.imagevenue.com/loc785/t..._122_785lo.jpg - http://img41.imagevenue.com/loc943/t..._122_943lo.jpg - http://img153.imagevenue.com/loc850/..._122_850lo.jpg
Note the inconsistencies between the Tcase temp and core temp in the last two replies
This is on the rare side and related to motherboard bios revision and or software corruption.
Referring to Tcase as T-junction is just plain silly.
T-juntion (or TCC activation) is fixed and between 85 and 100 C it is not software readable but closes enough to reference the actual digital temperature reading which the software calculates for you.
A Tcase reading in the 50s under load is well within the thermal guidelines and a temperature of 60C max is fine. (The advice was incorrect)
I have no opinion of TAT that I can share being that its design was intended for the use in the mobile platform
The problem is the discrepancy where Tcase is higher than core temp.
This makes both readings unreliable.
Update your bios and use the motherboard reporting software to monitor your temps.
Perhaps this will resolve the issue but there are no guarantees.
Uncleweb……
You’re bold.:D
Just an opinion,
Using an IR thermometer is acceptable for cooking a Turkey or even approximating ram temperature but highly inaccurate for thermal analysis that refers to internal temperatures or at least Tcase which requires an appropriate heat sink to stay within the thermal design guidelines.
56C is NOT TOO HIGH, whoever told you that you shouldn't exceed 55C is feeding you BS.
56C is WELL WITHIN NORMAL RANGE when running Orthros.
This is meaningless.Quote:
What that means is your actually loading @56/71-71 <---> 60/75-75 which is too high. Stay bellow 55/70-70 using Orthos.
...he says "your *accurate* cpu temp of 55 is too high"?? If 55C is accurate then you're absolutely within normal and safe limits. He has NO CLUE what he's talking about.
Trust me, you're fine.
This is how software tries to determine your TjMax:
http://softwarecommunity.intel.com/i....aspx#30228327
"Next you have to assume that the Tjunction is 100 degrees Celsius and if bit 30 of MSR 0xEE is set then it is 85 degrees Celsius."
The Intel rep says at the end of this thread that this is NOT valid for Desktop processors but I think temperature monitoring software continues to do this.
I used CrystalCPUID to do a RDMSR 0xEE and my E6400 shows bit 30 is set.
http://img477.imageshack.us/img477/8...msr0xeegv8.png
I can understand TAT reading this bit since TAT was designed specifically for mobile processors and has never been updated for the desktop core processors but if CoreTemp and SpeedFan are using this method to determine that my processor has a TjMax = 85C then they are wrong. All of these programs are in complete agreement but that doesn't make them all right. Instead it makes them all wrong.
At idle if my heatsink is 6C above my reported core temperature then my reported core temperature is wrong. The DTS represents the hottest point on the core. The heat transfer from the core through the IHS, through the AS5 paste and through the copper heatsink should result in a lower temperature for the heatsink and definitely not higher.
Using a TjMax = 100C for my processor gives me a lot more realistic number for my absolute core temperature.
I believe that TjMax is a fixed value but the other guys on this forum could be correct and my TjMax might actually be 95C or some other number around 100C. If I can get the heatsink off I think the IR thermometer should get me some temperatures very close to the real core temperature.
All I know so far is that assuming a TjMax=85C for my revision B2 Conroe core processor is wrong.
Also keep in mind that I am only using the Intel OEM heatsink which certainly isn't the most efficient these days. I have a Tuniq tower arriving later today which typically results in even lower reported core temperatures.
When I first got this toy and started using it I was getting some very inaccurate results. The shiny copper cup at the center of the heatsink could not be read properly so I covered it in some thin masking tape to take the shine off of it.Quote:
Originally Posted by kwalker
After doing that, the readings I'm getting now are very consistent. I unplugged my computer and let it sit for over an hour. When I came back the temperature of this cone was exactly equal to the ambient temperature so my readings of this cone are accurate.
The only way I'll be able to run a C2D with the heatsink off is to have a hand held fan blowing cool air on it. At low MHz and voltage, my C2D is only putting out about 20 watts of heat so this is certainly possible. If I can do this and can get a stable CoreTemp reading then I might be able to go in with the IR gun and get a reading for comparison. If nothing else it will certainly be interesting! Worst case, I see a new E6420 in my future. :D
My old Pentium III lived through worse torture than this.
Considering simple matters as the ambient temp, frequency and cooling that I have, I'm pretty confident of my assumptions.
coretemp 0.95 reports the following:
core0: 31°C (delta 54°C)
core1: 28°C (delta 57°C)
read interval 1000ms
My ambient is 21°C measured by analogic quality thermometer. The assumed TCC is 85° (by coretemp) and it seems accurate to me.
Thanks for the confirmation for those temps :up:Quote:
Originally Posted by blacksun1942
Still find it strange that CPU is higher then both Cores wich I understood should not be. Searched Google for an answer and didn't got any, but 1 thing it did notice me is that it occured on (most) Asus P5B boards.
Hehe when enabling PECI, I get lower temps for CPU (below the core temps). 16 degrees Celcius looks nice for CPU ;) :P
It used to seem pretty accurate to me too until my IR thermometer proved that it can't be 85C.Quote:
Originally Posted by RealTelstar
The new Tuniq just arrived. It transfers heat better than the OEM cooler so the core temp readings at idle, based on TjMax=85C, should decrease and look even more ridiculous.
At 1200 MHz and 1.100 volts at idle, my OEM heatsink goes from 22C to a steady 62C with the fan disabled. Those little cores in there are putting out a huge amount of heat even at those low settings. The DTS is always reporting from the hottest part of the core so I think people are under estimating the true core temperatures.
Even with the computer sitting in Stand By mode the cores put out enough heat to raise the OEM heatsink by 6C above room temperature.
Let's try to keep this thread on topic folks.
I think anybody new to this thread should read the ENTIRE thing a couple of times before posting.
Let's not turn this into a 'help me figure out my temperatures' thread. Start a new thread if that's why you are here.
I told you that low voltage / reduce multiplier test which proved your processor had a tj_max of 85 was not kosher. :p:Quote:
Originally Posted by unclewebb
I ran across that hardforum thread the other day but have not had a chance to read it yet. I see it is not accessible right now.
I continue to be impressed with all the abuse you put your processor through so that we may all better understand temperatures.
Hmm... perhaps I should invest in a thermometer :)
You were 100% right joebuffalo. My previous test seemed like a good idea at the time!Quote:
Originally Posted by joebuffalo
It has come in useful though. That is where the biggest temperature difference is found which proves that the accepted TjMax=85C simply isn't right.
SuperKeijo on the [H]ard forum used my test and was able to lower his core voltage down to about 0.69 volts and get his C2D to run at 600 MHz on his DS3 board. It became very obvious that TjMax=85C was not right for him either. He got things started by using an IR thermometer to confirm his numbers so I picked up a Fluke 62. I calculated at the reduced MHz and voltage that his C2D is likely only consuming 9 watts so he might be the first to pull his heatsink off for some true core temperature measurement. :D
Hopefully by early next week we'll all learn a little more. Either that or I'm going to have the first C2D keychain on my block.
You are a gentleman and a scholar. And a CPU abuser!
One thing you can also use the CrystalCPUID MSR Editor program for is to read your DTS directly.
The raw DTS data is located in IA32_THERM_STATUS which is located at 0x19C.
http://img234.imageshack.us/img234/9...dingdtsnq5.png
Bits [22..16] contains the DTS info. To extract that in the above example you chop off the 4 least significant zeros to the far right in EAX. The number 28 is the DTS. 28 hex = 40 C so on this core I am 40 degrees away from TjMax whatever that turns out to be. You can use this program to read this data for any core.
It confirms that CoreTemp is reading this value and displaying it correctly in real time. The TAT reported numbers are not always consistent with the DTS.
Location 0x19C is used in ALL Core processors, Solo, Duo, Core 2 Duo, Quad and I believe it was first used in the Pentium 4 Prescott series but I don't have one of those to confirm. The 85C TjMax number might have actually originated from the P4 era.
wow, had no idea my thread was still alive and kicking, I hardly visit this section of the Intel Forums :p
Very nice to see that many of you are testing/investigating and finding out a lot of new information on this matter. Keep up the good work!!! :)
The mystery of the absolute temperature of a Core 2 Duo has still not been solved.Quote:
Originally Posted by Miwo
I had a look at your results on the first page of this thread and would have to disagree with you. I believe your processor has a TjMax of 100C and you really were running it at over 90C.
These are just numbers and nothing to get too worried about. I've found that as long as your Orthos stable your C2D will be fine. I ran Orthos for half an hour one day and adjusted the CPU fan to keep it at 3 degrees from TjMax. In my case that was likely 97C and my computer was rock solid stable.
Yours is one of the few processors that I've seen that TAT is reading properly as TjMax=100C. Would it be possible for you or anyone that has a processor that TAT shows numbers above 85C to do a RDMSR on location 0xEE and post your results.
Refer to this post to understand what I'm talking about:
http://www.xtremesystems.org/forums/...&postcount=139
My C2D does not start to throttle until DTS=2. With a TjMax=100C that would be an absolute temperature of 98C. Your test showing your processor running at 94C and not throttling makes perfect sense. It wasn't hot enough yet.
http://img53.imageshack.us/img53/9646/tempwn3.th.jpg
Look at this.
Thank you for the MSR infor unclewebb. I knew the address of the MSR but was not sure how to really use it. For those people that have problems getting coretemp 95 to run without crashing your system, this is a solution to getting your DTS.
I tend to believe to coretemp 0.95.Quote:
Originally Posted by Bail_w
Also, I think newer C2D have 100° tcc (tjunction). I'd like to hear from people with supposedly ~100°C tjunction which week is their c2d.
I don't think TjMax=85C applies to any of the Core family of processors, mobile or desktop. I think it came about because a programmer or two misinterpreted bit 30 at location 0xEE and the misinformation spread from there.Quote:
Originally Posted by RealTelstar
My E6400 is one of the early ones which CPUz shows as revision B2 and is based on the original Conroe core.
E6400 - SL9S9
Batch#: L633A988
Pack Date: 12/05/06 ( May 12, 2006 )
You may be rightQuote:
Originally Posted by unclewebb
no one really knows at what point TCC activation occurs for actual core temp calculations read from the DTS.
with the introduction of the Q6600 and a few other newer processors the elimation of the Thermal diode takes away another factor (Tcase)
the temperatures are read directly from the DTS and discrepencys are surfacing in the software readings we thought were reliable.
I will keep following this thread
perhaps some light can be shed on this subject in time.
Just FYI
Send an email to Intel asking about temps and this what I get back.
Hello xxxxx,
Thank you for contacting Intel(R) Technical Support.
Please pay attention to the CPU temperature.
You do not need to pay attention to the core temperature.
If the CPU temperature is lower than 60.1 everything should be OK.
Sincerely,
Axxxx S.
Intel(R) Technical Support
:shrug:
doh!
we've been ignoring the "cpu" temp and looking at the cores so far...
Quote:
Originally Posted by Prefixxx
I agree there....because when i test Orthos and the CPU temp goes above 70.....Orthos fails nomatter what the Core Temp is....Core temp has gone upwards to 79 and has been stable.
but when i open my case side panel.....cpu temps do not exceed 63 degrees. with it closed it get to 70 and above and i have placed a fan everywhere i can think a sensor was located since i thought speedfan was actually reading the NB or PWN temp as CPU temps. but nomatter where i place the fan....the temps do not decrease.
the question here is: where is this cpu temperature measured?Quote:
Originally Posted by Prefixxx
looking at the figure of 60.1c i assume this intel guy is talking about tcase as documented in the processor specs. besides tcase is different for different processor families, unfortunately no software is showing this temp anywhere. the recommended method of measuring tcase is by putting a temp probe on the ihs. from looking at intel docs, this is a very tricky task and i doubt many people out here will do this ...
the cpu temperature displayed in bios or read by any other software is simply the temperature measured via the thermal diode and calibrated by some unknown factor. this reading would vary from motherboard manufacturer to motherboard manufacturer and even from one bios rev to the other. don't assume to reading tcase here!
I finally got around to doing some more testing today. I'm not quite sure what I've proven besides human stupidity has no bounds but I did end up with lots of interesting data.
I purchased a Fluke IR thermometer recently and a crazy guy at the [H]ard forum jokingly suggested that to get an accurate core temperature reading I should pull off the heatsink and the IHS so I can get a direct shot at the processor. That sounded like an interesting idea :rolleyes: so I decided to be the first on my block with a naked Core 2 Duo. I left the IHS on but after it booted up I pulled off the OEM heatsink and fan while it was running. Two strips of masking tape over top of the processor takes away the shine and helps ensure repeatable temperatures from the IR thermometer.
http://img465.imageshack.us/img465/2...stbenchsg0.jpg
To keep the processor from getting too hot I used an 80mm high speed hand held fan and had no trouble keeping the processor running in the 60C to 70C range.
http://img217.imageshack.us/img217/2541/66cqc1.jpg
CoreTemp 0.95 which uses a TjMax=85C for my E6400 was in agreement with the IR readings I was getting at 60C, 70C, 80C and beyond.
To explore when the throttle point kicks in I decided to put the hand held fan down and take pictures as the processor warmed up. Here was the last picture I took before things started to get serious.
http://img233.imageshack.us/img233/7682/84uh0.jpg
When the IR reported my cores getting near 85C, CoreTemp started spitting out these errors every couple of seconds.
http://img233.imageshack.us/img233/6979/warningfk7.png
I thought for sure a crash was imminent but it kept running as Intel Thermal Monitoring kicked in trying to regain control of this processor by throttling it.
http://img78.imageshack.us/img78/9858/badnewsqg6.jpg
We need a time out to explain the temperature numbers being displayed by these programs.
The DTS is a 7 bit number. What seems to be happening is DTS gets to zero and then when the processor gets 1 degree hotter the value in DTS goes from 000 0000 to 111 1111 binary. That is equivalent to 127. CoreTemp shows with a question mark that there is something wrong here and then reports the value in DTS directly.
CoreTemp -> DTS -> Real_Temp
84 -> 1 -> 84
85 -> 0 -> 85
127 -> 127 -> 86
126 -> 126 -> 87
125 -> 125 -> 88
SpeedFan and TAT work differently. They continue to use the standard formula of Real_Temp = TjMax - DTS so in this case they display:
Temp = 85 - 127 = -42
They report negative numbers starting at -42 and then as the processor continues to heat up the DTS continues to decrease just like usual.
The CoreTemp log file looks interesting.
http://img233.imageshack.us/img233/7986/logfilezy5.png
Core0 maxes out at a DTS value of 116 which, if my calculations above are correct, is actually 97C. Core1 seems to be displayed at a constant 85C reading when temperatures are out of control.
In the following graph, SpeedFan shows after it gets to 85C there is a sharp drop to -42 and then it continues to increase from there. Before my processor caught on fire I decided to put the hand held fan back on it and was able to regain control of this overheating processor.
http://img232.imageshack.us/img232/1...algraphdo0.png
After taking this processor to hell and back I learned something that I already knew.
The Core 2 Duo is a hell of a processor. :D
very nice find.....so what is the CPU temp measurement in Speedfan?
i find that Orthos fails when that hits 70 nomatter what the Core0 and Core1 temps are and nomatter what the cpu voltage is at 3.6Ghz.
I've gone back and forth but after seeing the results I would have to say that my TjMax really is 85C. I had no trouble stabilizing my processor at various temperatures from 60C to 80C and each time the IR thermometer reported a temperature within 1C of what CoreTemp with an 85C TjMax was displaying.
In my case, if TjMax was 100C like I had thought then that would have to mean that the individual cores are running 15C hotter than the IHS which is touching them. Without a heatsink attached, I can't believe that there is 15C of heat dissipation happening in only the thickness of the IHS.
The masking tape used on the processor for testing has previously proven to provide no difference in the temperature of the object underneath it. With my test computer shut down and unplugged for the last couple of hours, the IR thermometer reports the CPU to be exactly equal to the ambient temperature which validates my testing procedure.
If the above is all true and DTS = 85C for my processor then I would also have to conclude that the DTS sensor is not accurate at lower temperatures. Intel designed the DTS and calibrated it to accurately control the Thermal Monitoring functions when a processor gets near the TjMax point. It shouldn't be too surprising if it's not very accurate at reporting very low idle temperatures.
That also explains why Intel refuses to document an absolute core temperature for a Core 2 Duo. Any calculation based on the DTS wouldn't be accurate for the entire operating temperature range of the processor.
Most importantly, the XS guys seem to be 100% right, again! :D Trust the DTS and unless you want to invest in an IR gun, don't put too much faith in any absolute temperatures for the Core 2 Duo.
I'll try to post some temps of the copper plate on my new Tuniq when I have that up and running but I think I've learned all that can be learned when it comes to C2D temperatures.
Elisha: On my E6400 I have run Orthos stable for half an hour at 3200 MHz with my processor within a degree of starting to throttle. At 3400 MHz the absolute core temperature can't go beyond 75C while running Orthos before it crashes within seconds but it can run Orthos stable for hours at 3400 MHz as long as the core temperature stays down in the low 70C range.
If you are at or near your maximum MHz overclock then you will need to run your processor at a lower core temperature to maintain stability. The CPU temperature reported by SpeedFan is based on an inaccurate diode reading. Intel designed the DTS because the diode based temperature readings weren't accurate enough so ignore the SpeedFan reported CPU temperature.
How did you come to the conclusion that DTS was not as accurate at lower temperatures?
Here is the [H]ard forum where I've been discussing this issue:Quote:
Originally Posted by joebuffalo
http://www.hardforum.com/showpost.ph...&postcount=165
I did a previous test with just the OEM heatsink attached and then I used my 80 mm hand held fan to get my core temp down. This allowed me to get in there and measure the temperature of the copper core inside the heatsink without a fan being in the way.
Based on a TjMax=85C, CoreTemp was reporting a very steady 21C while the IR thermometer was reporting that the center copper cone of the heatsink was at 27C. That's impossible. The heatsink can't be warmer than the processor it's cooling.
I thought that must mean that TjMax for my processor is 100C but that doesn't seem possible after my test above.
From the data gathered my only conclusion is that the DTS can't possibly be 100% accurate from idle temps to DTS=0 temps. I'm really open to any other possible explanation for what I've found.
Just for fun I took my final graph yesterday and decided to use Photoshop to cut out the part of the graph when SpeedFan started reporting negative numbers. I moved that piece of the graph straight up and it fit into the upper part of the graph perfectly.
http://img53.imageshack.us/img53/351...lgraph2ki4.png
This seems to show that both cores continued to run even when the core temperature was up over 90C.
I think i want to invest in a IR thermometer for fun :)
There are other components besides the cpu that I want to check (ram and my hot scsi controller on top). what do u suggest under $50 and available in EU?
Unclewebb...just a thought.
If I understand your logic you seem to have argued the following: your previous testing suggested that a tjmax of 85 could not be right and you thus assumed it to be 100. However, your more recent testing is in favor of the 85 over the 100, thus you have now concluded that your tjmax may in fact be 85. In order to remedy the inconsistency of the former testing you conclude that DTS may not be accurate at lower temps.
Correct me if I am wrong about this summation, however, if I have stated the basic argument correctly, isn't a more plausable explanation simply that the tjmax you are looking for does not exist? Possibly DTS is accurate all of the time and the reason that you are getting conflicting results is not due to invalid DTS readings at lower temps, but instead because you are maintaining that your processor uses a tjmax variable of 85 or 100?
Every C2D has to have some fixed TjMax value associated with it where the processor begins throttling. It might be 85C or 100C or some number in between but it has to be some number. The problem I'm having is coming up with one number that explains what I'm seeing at both idle and at high temperatures.
Assuming a TjMax of 85C for my E6400 results in absolute temperatures reported by CoreTemp that are within 1 degree of what my IR thermometer is reading pointed directly at and hovering just above the cores.
Yesterday I had no idea what I was in for and the core temp went sky high as I was busy taking pictures and saving screen shots. I put the camera aside today and just concentrated on comparing the readings from CoreTemp to the IR thermometer. By adjusting the distance and angle of the fan to the cpu, I was able to run at a variety of temperatures between 48C and 70C without a lot of variation. I had plenty of time to slowly position the IR thermometer directly over the cores and obtain readings while the core temperatures remained steady.
The IR readings were generally the same as CoreTemp or within 1C at any point from 48C to 70C.
I installed a Tuniq Tower this evening and so far I've just been running it at low MHz and low volts. The ambient temperature is 23C and CoreTemp using an 85C TjMax is reporting 19C. That's not possible. Worse than this is that the copper plate on the bottom of the Tuniq which presses against the IHS is at 29C. For this to be possible, CoreTemp needs to be reporting at least 10C higher so that implies TjMax needs to be 95C for the idle temps to make sense.
TjMax = 95C is impossible at higher temperatures over 50C. How could two cores that are both at 60C only be heating the IHS up to 50C? The IHS is designed so that it is physically contacting both cores and the IR thermometer is located within 1 mm or 2 mm of the IHS.
That's the dilemma. There's no single TjMax number that covers both situations at idle and at high temps. The only thing I can conclude from this is that the DTS is calibrated and very accurate at the trip point but isn't as accurate at very low idle temps.
SuperKeijo on the [H]ard forums has also removed his heatsink and is experiencing this same dilemma during testing of his E4300 with an IR thermometer. Hopefully he'll have some more results this weekend.
RealTelstar: Extech makes IR thermometers and are available new on EBay for about $50 to $60. I think an IR-205 would be sufficient for this kind of testing.
Here is some proof that the CPU Temperature number based on the on board diode is a completely meaningless number.Quote:
Originally Posted by Elisha
http://img371.imageshack.us/img371/9625/speedfanfz8.png
With an ambient temperature of 22C the bios displays 13C when it reads this diode and SpeedFan reports 12C which are beyond meaningless. Turn it off and ignore it because inaccurate sensors can't provide you with any reliable information that can be used to determine anything.
Before I jump in on this discussion again, I want to state the point of this thread one more time for any new readers who have not taken the time to read all the posts:
Absolute temperature are worthless. All you need to know is DTS. Stop worrying about anything else!
unlewebb, your assumption that you are reading the core temperature as measured by DTS when you use your IR thermometer on the heatsink or even the IHS is just wrong. There is DEFINITELY a thermal gradient that you are simply ignoring. The reason Intel implemented multiple digital temperature sensors is because they knew that there are multiple hot-spots which could not be captured by a singe sensor.
From http://documents.irevues.inist.fr/bi...79/1/TMI23.pdf
(emphasis is mine):
"It can be seen that large temperature gradients exist on the
die. It also can be noted that some workloads display high
temperature gradients while other have no offset. Thermal
control algorithms need to prevent the hot spot from
exceeding the max temperature specification. It is possible
to mitigate the temperature difference by applying a fixed
offset to the diode reading. This obviously is a non
optimal solution as the workloads with low offset will be
panelized by the unnecessary temperature offset. The use
of digital thermometer provides improved temperature
reading, enables higher CPU performance within thermal
limitations and improves reliability."
If there are larger temperature gradients ON THE DIE surely they exist across the TIM, IHS, more TIM, heatsink, etc.
What does his tests about the e4300 conclude, has he been able to figure out if it has TjMax of 85C like your e6400 or is TjMax 100C as taken by tat/coretemp 0.95Quote:
Originally Posted by unclewebb
(I looked for it in the [H] thread, but couldn't find/missed his results)
The best thing about the digital temperature sensors is that Intel has taken the guess work out of the equation in thermal managemnet.Quote:
Originally Posted by joebuffalo
I do agree that the thread needs to stay on track but I was waiting for the digital pictures of a smoldering processor or better yet
Flames
:D
With TjMax and absolute core temperatures still undocumented by Intel, that statement remains true.Quote:
Originally Posted by joebuffalo
Here I disagree. I definitely haven't ignored the potential gradients and have even done some testing of this. Gradients exist when an application works one part of the core while other parts of the same core are mostly idle. For example this will happen if a program is working on a large calculation that involves mostly floating point operations. The floating point area of the core is going to be running at a hotter temperature than other surrounding parts of that same core. Here's how I tried to determine how big this gradient might be.Quote:
unlewebb, your assumption that you are reading the core temperature as measured by DTS when you use your IR thermometer on the heatsink or even the IHS is just wrong. There is DEFINITELY a thermal gradient that you are simply ignoring.
The process that is known to create the most amount of heat in a Core 2 Duo is MeromMaxPowerVer0p3.exe which is the name of the process that TAT runs when you tell it to run a load. I decided to run this process on one core while the second core was idle and then I switched the Affinity of this process while it was running to get it to immediately switch over and run on the second core so the first core now became idle. The difference in temperature between the two cores averaged 6C with the OEM heatsink and fan. With a better cooling solution the difference would likely be slightly less.
http://img112.imageshack.us/img112/6...ferenceog6.png
To me that represents a worst case scenario. Having one core running the most demanding program at full load heats up the other totally separate core to within 6C even though the second core is idle doing nothing. That surprised me because I was expecting a larger gradient to exist. This shows that the heat of each individual core is being shared with the other core and more importantly the graph also shows how quickly a core will decrease in temperature to its surroundings when it becomes idle. CoreTemp logging showed that this took less than a second for each core to stabilize at its new temperature.
With virtually zero load on both cores, with the heatsink and TIM removed and being cooled with a hand held high speed fan, the gradient between the two cores drops to zero. Both cores report that they are operating at the exact same temperature. Gradients are caused when part of a core is under load while other parts of the same core are mostly idle but if the entire core is idle than the gradients do not exist or are so small that they can be ignored.
The hot spots shown in the Intel diagrams are for a processor that is working but those hot spots don't apply to a processor that is idle and allowed to sit and stabilize at a fixed temperature.
A consumer hand held IR thermometer is not accurate enough to acquire rapidly changing temperature data from a processor that is under load but at idle, it's a different story.
The temperature of the cores at idle becomes the same and they also heat up the center of the IHS to a similar temperature. The round opening in the IR thermometer is approximately 1 square inch so it is taking data from both cores and the space between them and averaging it out to display one temperature number. My opinion is that at idle, the temperature gradient between the two individual cores and the IHS where I'm taking readings from becomes insignificant and certainly less significant than the 1% sampling error of the IR thermometer.
Sorry to disappoint. Not only were there no flames but this heat baked E6400 with the new Tuniq is running better than ever. More proof that you don't have to worry about overheating one of these things even if the heatsink accidentally falls off! :D
http://img207.imageshack.us/img207/720/3640mhzps6.png
Anyone who goes to Google to learn about C2D temperatures will sooner or later end up here so I think it's good to have some more facts which they can interpret as they wish to come to their own conclusions.
So far the E4300 being tested with a different IR thermometer is showing temperatures similar to what CoreTemp 0.94 is reporting which uses an assumed TjMax=85C.
Get a copper rod. Place one end in ice water. Heat the other end with a blow torch. There will be a thermal gradient along the bar. Yes? One end will be very hot, one end will be cold. In the middle of the bar, the temperature will depend on the location along the length of the bar.
We have the exact same thing going on here.
Let's neglect all the thermal conductivity killing interfaces that are present between the core and the heatsink for the moment. Let's assume we have a perfect heat conduction path from the core to the air.
You have a heat source (the core)
You have a heat 'sucker upper' (the ambient air)
There WILL be a thermal gradient along the path from the core to the ambient air. The underside of the IHS will be hotter than the top side of the IHS. This is a fact of life.
I *think* you may be getting caught up by assuming a steady state (where everything is the same temperature) is reached. But it is not. Heat is always flowing from the source to the sink. As a result, there will always be a thermal gradient. As such, you are not measuring the core temperature when you measure the temperature of the IHS.
I was faced with the same argument when I was taking temperatures of the copper cone at the center of the OEM heatsink. I agree that there is a gradient but the temperature being reported by the IR thermometer has not really changed.Quote:
Originally Posted by joebuffalo
I removed the heatsink so I could get a reading off of the IHS directly which takes the copper heatsink and the TIM out of the equation but the temperature results didn't significantly change. There was less than one degree difference when measured with the IR thermometer compared to when I measured the core temperature by measuring the other side of the copper heatsink.
joebuffalo: The C2D is individually calibrated on the assembly line. What likely happens is the processor is put into a socket and fed a minimal amount of voltage and run at a slow MHz similar to what I'm doing. SuperKeijo had no trouble running Orthos with his heatsink off because his motherboard allows him to run at a lower voltage than I can. The temperature can then be checked on the assembly line, likely with an IR thermometer or something similar and compared to real time readings from the DTS. Any necessary offset to correct the DTS to the measured temperature of the processor could be programmed into an on chip PROM type of memory which can't be changed later by the user.
My method of trying to read the core temperature with an IR thermometer might not provide me with the true core temperature due to the temperature gradients that you've mentioned but this method might be quite similar to how Intel calibrates their processors during manufacture. These are just my wild guesses based on nothing.
It really doesn't matter though. DTS is still king that no one can argue against.
What I do know now is that for my processor, when TjMax is assumed to be 85C, CoreTemp 0.95 reports absolute temperatures that are exactly equal to the temperature of the outside of my IHS as measured with an IR thermometer from about 45C to 85C. That may not be the ultimate true, blue core temperature but the CoreTemp reported absolute temperature number has plenty of meaning to me.
Testing has been fun. Thanks for all of your input. :)
Excellent thread guys..very informative :up:
I have gone through all the testing which you did unclewebb..I've concluded that speedfan 4.32 and coretemp 0.94 both report the correct temperature for c2d's since they assume TjMax of 85 degrees which you're testing have resulted....so is that correct and I can breath easy by just noting there values...i own an c2d E4300 proccessor myself btw..
Quote:
Originally Posted by abe786
NO!!!!
You missed the entire point of the thread. Just use CoreTemp 0.95 and check out the DTS readings directly.
Even if you agree with all of unclewebb's testing, HE DOESN'T HAVE AN e4300!
i have an e4300 and you CANNOT go by the temp readings. Go by the DTS reading on core temp 95. The temp programs assume variables that are not documented and may not even exist, DTS is documented and is accurate.
Yes, i've gone through the most of the thread and I do agree that DTS values is the way to go, but i wanted to find the safe temperature operating range for my CPU, since i was wanting to find out max overclock i can get with tempratures staying under control to prevent any long term damage...how can I do that with just DTS values, like for c2d its written that it shouldn't temprature shouldn't exceed 61 degrees for safety of the CPU...so to calculate it, I believe I need the TjMax value...Quote:
Originally Posted by joebuffalo
Unclewebb does mention that e4300 does have TjMax of 85 in post#176 (maybe he's borrowed that result from the hardforum guy whose also testing the CPU with IR thermometer)
the documented c2d temp of 61 degrees is an absolute temperature. This information is 110% useless to you in determining your safe zone for OCing because it is 100% impossible to ever determine an absolute temperature. Moreover, discussing tjmax makes little to no sense. The DTS number is a value that tells you very accurately how far your chip is from TCC activation. Temps guessed off of this are at best relative.
A good way to stay safe is by keeping your DTS over 20-30 in my opinion. Also use your fingers, check your ram, northbridge and HSF. Also make sure your system is stable, crashing is a good sign it is too hot.
What OC do you want and what cooler are you using? I didn't take my e4300 over 2.4 for a 24/7 OC on the stock hsf. With my new scythe mine I'll probably do a 3.0 24/7 OC.
Above all else, instead of attempting to use relative temps arrived at by guessing variables, skip the guesswork and learn to use what they are relative to--->the DTS
^^I'm running with stock cooler for now and OC is same as urs ie 2.4g, i get 22 as max DTS reading w/ TAT full load running on both cores...I will be getting a better cooler in coming weeks, with that I plan to run around 3.0ghz 24/7, maybe even more, if things are favourable...its a week 41 chip
By the way, the 20-30 DTS reading would corrospond to 65-55 coretemp 0.94 reading, so it may/may not be correct reading, but target's the same :D
TjMax exists for all processors but without this number being documented by Intel, all software is left guessing when it comes to reporting an absolute core temperature. If you don't want to invest in an IR thermometer and risk damaging your processor by running it naked and if you really want to see an absolute temperature number then I'd use software that assumes TjMax = 85C like SpeedFan 4.32 and CoreTemp 0.94 do. This is only for the Core 2 Duo and not the Quads and don't use this number to compare your results with anyone because they might be meaningless.
If you want a number that is 100% accurate, documented and guaranteed to have some meaning when it comes to C2D temperatures then stick with CoreTemp 0.95 which can be set to report the DTS directly, in real time, without any further bastardization of the number.
http://img234.imageshack.us/img234/3...tempdtszt0.png
The Core 2 Duo has a huge amount of head room and there are only two things you need to be concerned about.
#1) Throttling. When a C2D gets too hot it will throttle and slow down which no one wants to happen. My E6400 doesn't start to throttle until DTS=2 which is far hotter than what 99.999% of people run their cpu at so it's not really an issue, especially if you're overclocking.
#2) Stability. If you can run Orthos for 4 hours and if your processor is not throttling then you've got a pretty good system that will be able to run most real world applications without any problems. If you are Orthos stable and not game stable then you should concentrate on your GPU and making sure it is not over heating.
You're CPU is going to need more temperature headroom the more you overclock to maintain stability. Here's what my E6400 needs.
3200 MHz ~ 1.30 volts ~ DTS=5
3400 MHz ~ 1.40 volts ~ DTS=15
3600 MHz ~ 1.50 volts ~ DTS=25
Those voltages are approximate Orthos load voltages and the DTS values are approximately how much headroom I need to maintain stability. Everyone knows that as the MHz goes up you have to use more core voltage to maintain stability but I was a little surprised to find out that there is also a direct relationship when it comes to temperature. You need more temperature headroom the faster you go and reading the DTS directly is the most accurate way to monitor that.
Oh! unclewebb thanks for sharing...
I really suspect this, thats the reason I can not hit 3600 Mhz in my quadcore because the diference at 1,55 Vcore is no more than 15 º to Tjunction.
My Q6600 temps at load with 4 primes is 75º 75º 71º 70º at 8 x 400 = 3200 Mhz. That´s with thermalright Ultra 120 eXtreme.
That temps are at 1.375 VCORE set in bios with case closed, only one fan in Ultra 120 at 1400 rpm. I will try 3400 Mhz I think I can hit with only 1.425 VCORE in bios but my temps are near 80 º.
My temps are correct? Or is someone obtaining less.
Thanks
tal0n, how are you obtaining those temperature measurements?
If you just reported DTS we wouldn't have to ask that question.
so is this ok?
http://s2.supload.com/thumbs/default...0618223216.jpg
A DTS of 44 is completely safe.
That's my temperature obtained with core temp but not DTS. DTS must be setting in core temp to show how much temp is far from TJUNCTION.Quote:
Originally Posted by joebuffalo
If I have a 75º temp in my hottest core I have a DTS of 25º because my TJUNCTION in core quad is 100º.
cya
Hi, I bought a E6400 "L628B103"... This cpu is nice O/c'er , I use it 3500mhz def. vcore , and my cooler is TT bigtyphoon , but When I run the orthos small fft , it's up to 80 C !, before I have a E6420 and I used it 3.4 ghz and it's never to pass 60C ? I can't understand ?? please help !
vera, READ THE THREAD. Your absolute temperature are meaningless.
tal0n, if you are running at stock voltage, DTS=25 is a good number. I personally am at 30 but would not have a problem running at 20 one of these days.
I think unclewebb has shown us that you are OK as long as your processor is stable and you have just enough DTS that you don't start throttling.
BUT, just because the systems is 'OK' doesn't mean that you aren't putting extra wear and tear on the CPU. So leave some a margin with a bit of DTS if you want your processor to not have any problem down the road.
EVERYBODY, PLEASE STOP WITH THE "My processor is at 80-C. Is that OK?" POSTS? THEY ARE POINTLESS IF YOU WOULD JUST READ THE THREAD. Please don't turn this informative thread into junk.
so whats the verdict? im in a dilema on which temps to trust cuz core temp is like 15 degrees hotter than everything else. maybe i might want a new heatsink.
tvdang7 the answer is right above your question posted by Joebuffalo on 6/19. Please read the entire thread.
Interesting thread. I cant believe intel has stated an absolute max temperature of 61.4*C for my cpu (e6300), however they have not provided anyone (developers ets) with the appropriate tools / information with which they could design a temperature monitoring program. So they have said "keep your processor under XX*C for reliable operation, but we have no way of measuring the absolute temperature. Once processors start being affected by degradation caused by overheating, what will they do? Ask the end user if they ran it out of spec! How do we know, we dont know its temperature! Intel appear to have designed a loop hole, sidestepping their responsibility to the customer. If they stated a DTS value and said keep over that for reliable operation it would be different. However even using the DTS value is dubious - it is simply a fixed number (85 or 100) at which the program tells you the cpu shuts off at - the REAL temp may be above or below that number. It is calibrated so when any given processor is at its individual and unique max temp, DTS = 0.
Timbosan: That 61.4C number is the maximum recommended case temperature (Tcase) at TDP which is measured on top of the IHS at the geometric center. It's not the maximum safe temperature the processor can operate at. That's controlled solely by data from the on chip digital thermal sensors (DTS).Quote:
Intel: The TDP specification should be used to design the processor thermal solution. The TDP is not the maximum theoretical power the processor can generate.
PROCHOT# is asserted whenl DTS=0 which Intel documents to be "the maximum safe operating temperature."Quote:
Intel: As an output, PROCHOT# (Processor Hot) will go active when the processor temperature monitoring sensor detects that one or both cores has reached its maximum safe operating temperature.
Processor shutdown or THERMTRIP# does not occur until approximately 20C after TjMax for the Desktop core processors or at a documented absolute temperature of approximately 125C for the mobile Core 2 Duo processors.
The Core 2 Duo has a huge amount of temperature head room and as long as the DTS reports a positive number you are operating it within the Intel specifications and you aren't voiding your warranty by doing so.Quote:
Intel: Regardless of enabling the automatic or on-demand modes, in the event of a catastrophic cooling failure, the processor will automatically shut down when the silicon has reached a temperature of approximately 125 °C. At this point the THERMTRIP# signal will go active.
The safe operating temperature, processor throttling and shutdown are all controlled by the DTS. It's the only temperature data you need to know.
Ok i asked intel what the maximum operating temperature of the e6300 is, as i was worried about keeping it within its specifications. This was the response:
"I understand that you are concerned about the operating temperature of the Intel(R) Core(TM) 2 Duo processor E6300.
The maximum operating temperature of the Intel(R) Core(TM) 2 Duo processor E6300 is 61.4 degrees Celsius. As long as the processor is operating under this temperature it is operating within specifications."
That implies the cpu should not exceed 61.4*C or it is "out of spec".
I then asked what software i should use to monitor the temperature with, as i would need to be able to ensure the cpu was operating within spec. This is the response:
"Regarding your first inquiry about monitoring software, thermal management and sensors are built into the motherboard; therefore, the motherboard manufacturer should be the ones providing a monitoring solution that can read the information from the processor.
Intel would only count with monitoring software that is specific to Intel(R) desktop boards and not to the Intel(R) processors; I would recommend contacting your board manufacturer for the application you need to run to be able to verify on the processor temperature and voltages.
As well, the PECI option is a feature that is particularly handled by the system chipset and BIOS meaning that Asus* (i told them i have an asus mobo) would be the ones recommending whether this option should be enabled or disabled in the BIOS"
This is a problem, as how could asus have been able to design accurate temperature monitoring software? AFAIK there is no accurate extrapolation possible of any values the thermal monitors output into absolute temperature, without a TCC (TjMax) being documented for the core 2 duo.
Timbosan: Sounds like Intel hired a summer student and put him in charge of the C2D Temperature FUD program.
The green guy you talked to has never read through the Intel data sheets. To properly measure the case temperature of a processor you have to cut a groove in the heat spreader (IHS) and run a thin thermocouple wire to the geometric center of the processor. Sounds like a lot of work for the average person to see how their C2D is running. I think I'll stick with the much simpler and fully documented DTS readings.
I'm getting multiple readings on my phase cooled e6600 as well.
Motherboard sensor said -36C so i figured okay to boot.
CoreTemp says around 4C for cores 1 and 2, as does speedfan. It is interesting, however, that speedfan reports -27C for CPU temp.
Does this mean the cpu is running at 4 or -27 or both depending on where it is measured?