http://www.fileden.com/files/2006/6/20/80195/temps.jpg
Which do I trust? How can I find out which one is the most accurate? Crank up voltages + speeds until I start throttling at the 85C mark? :(
Printable View
http://www.fileden.com/files/2006/6/20/80195/temps.jpg
Which do I trust? How can I find out which one is the most accurate? Crank up voltages + speeds until I start throttling at the 85C mark? :(
IDCC is reporting the thermal diode not the core temps and it looks correct in relation to TAT. Coretemp just looks wrong.
coretemp is real temp ;)
Really? Confirmed with a 3rd party temp sensor taped on to CPU core or something? I figured TAT would be the most accurate..
Just interested because you seem so sure, suprised me..
mabey cause its a 4300?
although do they show that when only one by one are turned on.....some monitoring apps screw up when there are other monitoring apps on....
hrmmm.....Quote:
Originally Posted by NickS
well, i guess ill watch ThrottleWatch, and tone down my fan to try and get past 85C. If it throttles, ill know which one is accurate...
Wow, good idea! Just be careful ;)
Quote:
Originally Posted by NickS
i think TAT will throtle it when it sees 85 ish....
when c2d came out and before it became common knowledge that not all are the same concerning temperatures, cause of IHS and stuff i played with "overheating" mine quite a bit, i couldnt believe the temps and was also wondering when it will throtle and shut down....well i throtteled it 100 times and even let it shut down at 111c (asus probe) a few times and the chip is still running strong, they seem quite durable......oh ya in the end my chip just needed lapping......
but in case of this thread i think it might be some bug/incompatibility more than such high heat, its a 4300 allendale afterall
Update....
http://www.fileden.com/files/2006/6/20/80195/temp2.JPG
Turned down my fan until I could barely hear it. Looks like Eva is right......or this Throttlewatch is broken >_<.......
it's a known fact that IDCC reports the core2 cpu's legacy temp sensor versus Coretemp's digital sensors.... also TAT and throttlewatch probably hasn't been updated for E4300 and TAT was never meant for public release http://i4memory.com/showthread.php?t=3265
I've tested a few core2 cpus across alot of boards and coretemp is pretty consistent at my known 24/7 stable oc of 3600mhz at 1.37-1.43v vcore resulting in similar temps for coretemp. TAT/and board software all differ from board to board.
lmao...so after that testing I just did there is a possibility that ThrottleWatch is broken for e4300, or a combination of all things being broken...
Eva, I will take your input on CoreTemp being the most accurate because it sure seems that way when I feel the temperature using my finger. When TAT reads 90C, the heatsink was warm/hot to the touch, but not so hot that I couldn't keep my finger on it
I will try one more test to try and eliminate Throttlewatch as a source of error, and that will be running a bench when my TAT temperature is over 85C. If my results are subpar then what they usually are, ill take that as throttling
i think throttlewatch doesnt work with c2d anyway use rightmark RMClock, or just look at cpuz to see is the speed is lowered
Last Update:
http://www.fileden.com/files/2006/6/20/80195/temp3.JPG
Eva is definitely 100% right on this. Processor hasnt throttled and I see no decrease in performance. Overall I must say that this was a nice good fun learning experience for me. Since I know CoreTemp is accurate, time for more OCing on my new E4300 with my sexy jam packed HTPC Desktop case on Air
thats what i have posted over in the abit aw9d-max forum to clear things up:
Case Temperature
intel thermal specs always references a case temperature (TC). this TC is defined as the temperature measured at the geometric center of the package on the surface of the IHS.
X6800 TC = 60,4C
C2D with 4MB L2 cache TC = 60,1C
C2D with 2MB L2 cache TC = 61,4C
PROCHOT#
the system bus signal PROCHOT# will go active when the processor temperature of either core exceeds its maximum operating temperature. this indicates the Thermal Control Circuit (TCC) has been activated. the temperature at which the PROCHOT# signal goes active is individually calibrated during manufacturing. once configured, the processor temperature at which the PROCHOT# signal is asserted is not re-configurable.
THERMTRIP#
the processor will automatically shut down when the silicon temperature has reached its operating limit. at this point the system bus signal THERMTRIP# goes active and power must be removed from the processor. the temperature where the THERMTRIP# signal goes active is individually calibrated during manufacturing. once configured, the temperature at which the THERMTRIP# signal is asserted is neither re-configurable nor accessible to the system.
Digital Thermal Sensor
the Digital Thermal Sensor (DTS) is the on-die sensor to be used for fan speed control (FSC). each core has its own DTS. the DTS is monitoring the same sensor that activates the TCC. readings from the DTS are relative to the activation of the TCC. the DTS value where TCC activation occurs is 0 (zero).
Core Temp
as far as i know, thats the point where core temp kicks in. core temp just reads two registers. the first one is the one which holds the temperature where TCC gets activated, the second one is the register holding the DTS value itself. all what core temp has to do, is subtract the DTS value from TCC activation temperatur to get current core temperatures. as i understand, core temp displays the TCC activation temperature as "Tjunction" and the actual temps of both cores under "Core #0" and "Core #1".
thats how i understand this after reading intel C2D processor specs, intel C2D thermal guidelines and core temp description ...
so, as long as TCC is not activated (the cpu is not throttling) temps are below the 85C core temps shows as "Tjunction". i guess throttling could also be seen within cpu-z as reduced clockrate. have not yet tested this, anybody seen this already?
in this case we safely can assume TAT is wrong. somebody mentioned already, TAT was not written for this processors. it is a tool designed to test mobile cpu's. as this temps are read from registers, it's likely TAT reads the wrong register ...
After playing with my E4300 I too am reasonably sure that CoreTemp is NOT reading these chips correctly as I have stated in my E4300 quick test shown HERE
You understand it correctly, and a nice explanation :)Quote:
Originally Posted by fgw
From those screenshots, it seems that TAT has somehow come to the conclusion that the E4300 has a "Tjunction" of 100C, while Core Temp checks the MSR and gets the proper value, which is 85C.
It could be a result of the CPUID value of this stepping, its below 6F4 (the first public ES aka B0 rev)
So its possible that TAT automatically assigns 100C as Tjunction, without even checking the proper MSR.
Greetings!
Nice thread! :clap:
I was also having trouble figuring out which reading software was correct in my E4300.
Speedfan, CoreTemp and TAT were all showing different temperatures. :confused:
Greetings!
Enabled CPU TM Function and PECI in BIOS.
The E4300 is at 2,7Ghz, 1,35v.
Ambient temperature is 17-18ºC
In idle:
CoreTemp reports 12ºC+16ºC
Speedfan 9ºC
TAT 28ºC+30ºC
Its impossible that, using a Zalman 9700 as heatsink, the CPU is bellow ambient temperature. :confused:
so from your results, TAT is more accurate than the others.Quote:
Originally Posted by impar
this makes things even more confusing now. So the accuracy is depended from board to board.
Greetings!Yep. I cant get myself to believe CoreTemps readings.Quote:
Originally Posted by andylihaha
Currently, the ambient temperature is 15ºC and CoreTemp reads 13-16ºC.
Motherboard is P5B-Deluxe with 0910 BIOS.Quote:
Originally Posted by andylihaha
A similar thread turned up in OCForums:
http://www.ocforums.com/showthread.php?t=497920
Also, SpeedFan is definitely off. With PECI enabled it read 9ºC, with it disabled it read 22ºC, and after one minute of Orthos it reads 79ºC now, after I turned Orthos off 10 minutes ago.
Could Miwo had the throttling feature disabled when he performed the test?
PS
Another thread in another forum discussing the same issue:
http://www.hardforum.com/showthread.php?t=1151311
Many experienced people are contradicting each other here and in other threads...
Is there any consensus clarity on what is the most accurate core temperature monitor? Say for a Conroe and a P5B-D? CoreTemp the most accurate?
As it stands ... my PC probe II, TAT, and CoreTemp beta 94 are markedly different... While I understand the rationale, I dont think the answer "trust monitor X because it shows the highest temperature" is a good answer.
I have a ES HSF coming (supposedly) and I need an answer...
unfortunately you are out of luck!Quote:
Originally Posted by Battle_Rattle
i have read a lot of documents and forums on this issue. to sum it up:
no matter what tool you are using, all this programs have to rely on sensors integrated within the cpu to measure temps. intel supplies two ways to measure temps:
- the old fashioned thermal diode, readable via PECI interface
- digital thermal sensor (dts, introduced with conroes), readable through registers
the problem is as follows:
the thermal diode let you read an absolute temperature BUT is not very accurate AND needs to be calibrated in order to show correct temps! programs using this method will show slightly different readings depending how accurate the program developer calibrates his software.
on the other hand, dts is very accurate. as intel is intended to use this sensor for fanspeed control, this sensor DOES NOT DELIVER ABSOLUTE TEMPERATURES! i gives a reading how far the core is away from the point the cpu starts to throttling. all programs using this accurate sensor have to calculate absolute temps by subtracting dts readings from the mentioned throttling activation temperature. to make things even worse, intel did not supply this temperature value in any register as far as we know yet. thus, software has to "assume" this temperature value and do the calculations.
you can figure out yourself the probability, the programmer hits the correct value just for your very own processor.
this temperature value is burnt into the processor at manufacturing and may vary from die to die.
as said before: as this temperature value is not readable via any register, you are out of luck!
in your situation, you can of course use any program (i would recommend coretemp) and compare readings from one situation to the other. e.g. when changing the fan you can see the change in temps. this change is very accurate. but it is impossible to compare temps between different processors even if they are of the same type ...
very interesting :)
take a look at the screen below
temp on asus p5b dlx with waterchiller ( liquid -3C)
i think that coretemp it's the most accurate also.
http://i126.photobucket.com/albums/p...adi/th_002.jpg
I dont even care about temps, i just try to stay away from the throttling point by about 10c for myself and other than that i dont care if my temps are xx or xx ....... but core temp is the one that is comparable to other mobos and setups, you just cant compare asus probe to gigabytes whatever ... other software like speedfan, everest, mbm actualy only shouw what probe (in this case) would show.... o another note when i put in a quad cpu probe showed 1/2 temps
In RD600 cpu throtlles @ 85c via smartguardian. Shutdown temp set in bios also reads same temp. this is not the same temp that Coretemp displays(61c).
So, unless it's the bios @ fault on RD600, Coretemp is not reading correctly. I have same issue too, reading 19c idle in 25c ambient, using AIRCOOLING.
this being said, coretemp reports same temp across many different boards for same cpu, when voltages/cooling are the same. Although the temp may not be perfectly accurate, it's the best we got ATM.
core temp showed normal temperatures for me....it was asus probe that showed 1/2 temp
i agree completely! the point is to keep some sort of safety margin to the throttling point. as i said already, this point is different from cpu to cpu AND can't be read by software. so software like coretemp is using either 85c or 100c as throttling point, which might be correct on some cpu's but is definitely wrong on others.Quote:
Originally Posted by Millyons
don't get me wrong, im not blaming the writer of coretemp! this is completely intels fault for not providing documentation of this features to the public. i'm still a great supporter of coretemp!
would be a nice feature if coretemp would also display the dts reading directly just showing the room left to the throttling point. i already requested this at the coretemp forum. lets see if "The Coolest" will implement this in a future release.
this is a good example. i'm pretty sure, coretemp is using the wrong throttling temp on your specific cpu and therefore fails calculating the absolute temperature correctly.Quote:
Originally Posted by cadaveca
Yes, i too think it's the best ATM, as long as you are using it on a cpu where coretemp gets the throttling point correctly!
Just Got a e4300+p5b, and i'm facing the same issue, TAT, Coretemp, PC Probe all showing different temperatures w/ temp reported by TAT higher than about 15 degrees compared to coretemp...and PC Probe shows an inbetween value...
So any updates on the issue....what to trust..:confused:
Greetings!
I decided to trust TAT.
CoreTemp was showing sub-ambient temepratures on idle, using a Zalman 9700.
I am running the latest speedfan, coretemp and TAT, speedfan and coretemp agree and at stock under full load with 20C ambient and stock HSF I am reading 35C which I think is very reasonable TAT would have me believe it is nearer 60C which I dont think is right.
TAT was not meant for the E4300 and seems to have problems reading the temps whereas the latest coretemp is supposedly updated for the E4300.
If you have an E6XXX series CPU TAT probably is correct but I think for E4XXX it is not trustworthy.
I have a DMM with temp probe and I will try to get it onto the IHS if I can and see what that gives us, may take a few days though as im a bit busy at the moment :(
^^Ahh DMm w/ temp probe...u can end this mystery for once and for all..
Would be looking forward for u'r results :toast: ...Do take u'r time
Regards,
Use TAT for E4300s :)
I will be interested to see your results though sparky1000 :)
i doubt this temps are correct. 35c under load seems pretty low to me. well, depends what you understand under full load, but the 4300 i tested runs way hotter. don't remember vcore i used, have to check, but it was somewhere around 1.40v. coretemp readings were in the mid 50ies and i have to add 15c in order to get something near to real temps, as coretemp is using a wrong temperature offset in temperature calculations on certain processors. thus, in your situation i would assume temps near 50c which at least to me is far more realistic than 35c and still are good temps for stock hsf.Quote:
Originally Posted by sparkY1000
waiting for the next release of coretemp as "The Coolest" probably will add the feature of showing real dts values in addition to absolute temps. this will allow us to read relative but accurate temps which are correct for ALL processors supporting dts!
reading relative temps we are loosing the ability to compare temps from one processor to another but analyzing load temps or cooling efficiency on very one processor will do just fine!
don't care about the absolute temp values coretemp shows. focus on temp changes reported by coretemp as this changes are accurate: e.g. if temps go up by 10c than temps changed by exactly 10c. point! if this change was from 50c absolute up to 60c absolute or from 53c absolute up to 63c absolute - you simply can't tell!
New speedfan out... direct C2D support.
^^New Speedfan's reading is same as CoreTemp's....
So it means, coretemp was right all the time..?
I think until we have some definite answers believe the highest temp as you will be alot less likely to kill your chip that way :(
http://img63.imageshack.us/img63/9260/tortureuc4.png
On my P5B Deluxe with an early Conroe E6400 CoreTemp seems to be reporting 100% correctly. At 85C thermal throttling was active on both cores and it couldn't go any higher just as Intel intended. I think TAT was reporting 2C too low.
CoreTemp seems to have a problem with the E4300. If it reports your idle temps lower than ambient then I would suggest adding a correction of 15C (100C-85C) to the reading and it should be right. Not all E4300 chips are being misread but there is definitely a problem on some boards and not others.
I hope it gets sorted soon as my E4300 really wants to fly! :D
I'm one with CT reporting idle temps below ambient with 4300. From reading here and elsewhere I'm convinced that CT is performing its calculations based on an incorrect t-junction for this proc. As mentioned previously, this introduces a ~15 degree error. Using TAT 'til fixed-better safe than sorry.
Use the new speedfan and offset your core temps by 15C it is alot nicer to use than TAT and speedfan can sit in your taskbar giving you warnings if your CPU gets hot.
Also is it normal for E4300's to be v hot!? I am running @3.0GHz 1.3375V (in BIOS about 1.29V real) with F@H running and the stock heatsink seeing 60C loaded temps!
I am getting water sometime next month but would love to know what other people are getting with the stock cooler under load.
I read in the big BX2 thread that speedfan had been updated and now works with the badaxe2. I'll give it a try when the box is back up. Currently I'm suffering from either a global shortage of female AUX molex pins or some sort of conspiracy to prevent me from acquiring any!Quote:
Originally Posted by sparkY1000
Mine was running pretty warm as well-~55-58C (TAT) Orhos mix priority 9. This as in my sig. Orthos failed in a few minutes @ 333 but I didn't play with voltages. Will mess with it more when I'm back up of course.
BTW-using stock cooler.
It appears that "The Coolest" has released coretemp 0.95 today which purports to fix the temp reporting problem with the 4300s.
Technically it's not a "fix" just an adjustment of the Tjunction value from 85C to 100c for E4300s which will mean CoreTemp will read 15C hotter now.Quote:
Originally Posted by mezcal
Does anyone know what the Tjunction value should be for E4300s?
New Coretemp causes my system to restart! No matter what as soon as I open the new coretemp up it restarts my machine! LOL!
It gives the Tjunction value and the dts in only a calculation based on that value. You can quiet easily work out what the DTS is actually reading.Quote:
Originally Posted by fgw
yeah, that seems to be common.Quote:
Originally Posted by sparkY1000
http://www.alcpu.com/forums/viewtopic.php?t=237
Sorry man, thats not throttling. When throttling occurs TAT will show you the throttled speed of the CPU.Quote:
Originally Posted by unclewebb
My experiment with throttling on E6600 on BadAxe revealed that Throttlewatch didnt work. Anyone seen it working with C2D's?
Heres my previous CPU (E6600) without fan on the cooler at 1.6volt, its supposed to be running at 3.6GHz, as you can see in the top right corner. Now thats what i call throttling =)
http://i8.photobucket.com/albums/a5/...T_Throttle.jpg
i agree! just would be handy to show plain dts value without recalculation! if i understand the new feature list corrcectly, the coolest already implemented this feature.Quote:
Originally Posted by SLi_dog
unfortunately coretemp 0.95 reboots my system as soon as i run it, so i'm not able to verify this.
anyway, i think we all should get rid of this "absolute temperature measuring" thing:
using plain dts value instead maintains accuracy provided by dts readings and shows how far the processor actually is away from TCC. intel implemented temperature readings on c2d to use it for fan speed control and here they just need to know how far is the temp away from TCC activation.
- there is no way to read tjunction, in fact its thermal control circuit (TCC) activation temperature, although everybody calls it tjunction
- this TCC activation temp is calibrated during manufacturing, IS NOT software readable after calibration AND might differ from die to die! the 85c or 100c value is just an approximation of TCC which results in all temps calculated from this value are more or less accurate. monitoring software could not read this 85c or 100c directly, as there is no register to read it from. instead a single bit in a register is read and depending on this bit if set or not 85c or 100c is used during temperature calculations. as of intel, this works for mobile cpu's but not for desktop and server processors. on desktop and server processors, this bit might hold any information and thus on some steppings lead to the assumption of 85c on others to 100c!
i agree, it would be nice to read absolute temperatures directly, but as the way this is implemented currently, this is simply not possible!
yes, rmclock shows the multi and vid dropping as soon as throttling kicks in.Quote:
Originally Posted by ted3
tat is not working on my abit board ...
SpeedStep is supposed to be enabled in BIOS to allow TAT throttling, isn't?
Elsewhere, 85C is not an absolute value. Recall what fgw said to best understand:
So, throttling can occur at 85C or something else.Quote:
Originally Posted by fgw
Well so how many of you are OCing the e4300....I've been waiting for this bug to get sorted out, before starting to OC it, but now from the looks of it...the mystery only deepens with new coretemp readings..
But Somehow i believe the temps reported by earlier coretemp(or new speedfan) are the correct one, b'coz other guys are OCing this chip to around 3.6-4GHz, surely it would run very hot at this speed, if this chip runs this hot(as suggested by new coretemp) and chips would start throttling but SuperPI scores dosen't seems to suggest so...
you got it! the way coretemp works, throttling occurs at the point where one of the cores shows exactly the same value as is displayed as tjunction in coretemp. this might be any other value in programs reading their temperature off the thermal diode. i assume rmclock does so, as rmclock shows slightly different values than coretemp.Quote:
Originally Posted by psy4fun
but nobody can tell if this temperature displayed in coretemp as 85c is actually 85c, 83c, 88c, or even near 100c (assuming coretemp is using the wrong tjunction) ...
you see, playing around with absolute temps leads nowhere. thats, why i requested The Coolest to implement displaying plain dts values in coretemp. was not able to verify this yet.
This does not make sense at all. Since Tjunction temperature does not exist in desktop processors, why would a fix be required? If you are already assuming that a Tjunction temperature exists(which is fault assumption too, as we all agreed), why not use the same Tjunction for E4xxx as well as E6xxx. I can understand why reporting C2Qs as 100c Tjunction makes sense, but I don't understand this logic with the E4300.Quote:
Originally Posted by SLi_dog
This would confuse many users that will now believe their E4300 operates at a much higher temperature. If any fix was to be applied, then it should be on TAT itself. Or instead, reporting only the DTS value(as fgw suggested) might be a better solution.
This is very fishy and may damage the integrity of the conclusions which we all now believe in. While the absolute temp reading CT gives may be incorrect in many cases, it should always start throttling at 85C with C2D cpus, and 100C on C2Q cpus and some E4xxx. Obviously this is not real temperature, but it does indicate the throttling point. If this is indeed so, how is it possible that this guy encountered throttling at 61c in Coretemp?Quote:
Originally Posted by cadaveca
no, nobody does! the only way to find out is to push this cpu to its limits and see what temps are reported by coretemp when throttling starts...Quote:
Originally Posted by SLi_dog
most of the time PROCHOT# (TCC activation) temperature erroneous gets referenced as tjunction! coretemp uses this TCC activation temperature as a reference point to calculate temperatures from. TCC activation temperature can't be read by software, BUT there is a bit in a register (we discussed this a few posts earlier) which was implemented by intel. this bit is valid on mobile processors and defines if TCC activation temperature is near 85c or near 100c! i use the term "near" because in reality, this temperature is calibrated on a processor basis and differs from die to die. on one processor die it might be 87c while on an other processor die it might be 83c! coretemp, as i assume all other programs using DTS, uses this bit to decide if for a certain processor 85c or 100c has to be used in the calculations. although this is valid only for mobile processors, this seems to work also for most current BUT not all desktop processors too. we have seen more and more new processors coming out where this assumption is not correct anymore. thats the situations, where coretemp reads temps about 15c off!Quote:
Originally Posted by GGuyZ
so, to get coretemp back to more valid readings, the only thing to to is to change the reference temp from 85c to 100c instead on relying on the obviously wrong set bit in the register. that was done in coretemp 0.95 for e4300 and may be some other processors too.
well, in fact the new 15c higher readings might be the correct readings. i have a second rig with one of this e4300. unfortunately i have not yet pushed it into throttling. this is the only way to figure out which temp is right. for now i would assume the "new" 15c higher reading is correct. i can hardly believe, that my e4300 running on air keeps temps at 55c under full load! its far more realistic, that it should read 70c instead. will verify this as soon as i get my hands on this rig ...Quote:
This would confuse many users that will now believe their E4300 operates at a much higher temperature. If any fix was to be applied, then it should be on TAT itself. Or instead, reporting only the DTS value(as fgw suggested) might be a better solution.
unfortunately i don't have any information on smartguardian and so cant say anything here. you are right, this does not fit very well into this picture. different polling intervals might play a role here.Quote:
Originally Posted by cadaveca
In RD600 cpu throtlles @ 85c via smartguardian. Shutdown temp set in bios also reads same temp. this is not the same temp that Coretemp displays(61c).
So, unless it's the bios @ fault on RD600, Coretemp is not reading correctly. I have same issue too, reading 19c idle in 25c ambient, using AIRCOOLING.
this being said, coretemp reports same temp across many different boards for same cpu, when voltages/cooling are the same. Although the temp may not be perfectly accurate, it's the best we got ATM.
This is very fishy and may damage the integrity of the conclusions which we all now believe in. While the absolute temp reading CT gives may be incorrect in many cases, it should always start throttling at 85C with C2D cpus, and 100C on C2Q cpus and some E4xxx. Obviously this is not real temperature, but it does indicate the throttling point. If this is indeed so, how is it possible that this guy encountered throttling at 61c in Coretemp?
cadaveca, did the cpu throttle at 85c or did the bios shutdown the system as the bios is set to 85c too? may be smartguardian did not signal throttling correctly? there is a tool called rmclock, which i use to check throttling. may be you can give it a try http://cpu.rightmark.org/products/rmclock.shtml
You probably did not understand me correctly. First, where did you read that Tjunction is calibrated specifically for each processor. This does make sense, and while I'm aware that PROCHOT# and THERMTRIP# temps are calibrated in the making process, I'm uncertain the same applies to Tjunction. The reason I'm uncertain of this is because the MSR bit you were talking about(bit 30 of MSR 0xEE to be exact), have held constant information(either 85C or 100C as you mentioned) in the mobile processors.Quote:
Originally Posted by fgw
Second, this bit may be valid in many desktop processors, but it has no official reference in Intel docs! It is possible that this bit information has been left by mistake, but it has no real use. Why am I saying this? Well, because in the intel dev forum it has been made clear that trying to derive the real temp from the pseudo Tjunction Temp is wrong. What I don't understand is why the CoreTemp program developer keeps following this mistake, while he knows this unfortunate fact.
throttling tests cannot help much in determining whether the CoreTemp reading is closer to reality when calculating 100c or 85c. In the previous case, throttling would have started at around 85C core temp. Now it will require 100C to begin throttling, but this has no indication on real temps.Quote:
Originally Posted by fgw
I'm very interested in this as well.Quote:
Originally Posted by fgw
I am totally onboard. Who cares what the absolute temperature is. It requires us to guess what the 'tjunction' is set at. But we do know, without any guessing, what the 'delta to tjunction' is thanks to Core Temp 0.95. So that's what we should be looking at, yeah.
Riddle me this, though. How small can we let that delta get before we are pushing it? Does anybody have any recommendations for how close is too close for a load (100% TAT load) temperature?
i see we are talking the same language ... ;)Quote:
Originally Posted by joebuffalo
well, i will handle it this way:Quote:
Riddle me this, though. How small can we let that delta get before we are pushing it? Does anybody have any recommendations for how close is too close for a load (100% TAT load) temperature?
- i don't want my processor to start throttling -> keeping dts readings greater 0 would be enough in this case! you might add some safety margin, lets say 10c or 15c, just in case. this would be fine as long as the processor is not overclocked or better said as long as vcore is at default setting.
- as soon as vcore is raised, this might be a little different: some time ago, i have read a story on thg about extreme overclocking and there was this link to the physics behind electromigration. don't want to comment on the thg story as i have the feeling they did not interpret it right, and also don't want to warm up old dishes again, but to make a long story short and if i understood the readings correctly: if vcore is increased, current flow increases and thus does current density. double the currentdensity requires 20c lower temps to NOT run into increased electromigration! currently i'm running a vcore of 1.50v and coretemp 0.94 (unfortunately 0.95 fails on my system) reads 50c to 55c under full load. this would translate to a dts reading in the range of 30c to 35c and seems sufficient to me.
Wow, you must have some great cooling going on there.
What are you using to load your system?
I am running an e4300 at 2.8-GHz with a Ninja/Yate Loon cooler and I'm getting DTS readings of about 30 when loaded with TAT.
dont forget i'm on water!Quote:
Originally Posted by joebuffalo
i use orthos to load my system. small ffts to produce maximum heat and blend test to verify stability. currently running some blend tests at various vcore settings.
regarding your e4300: in a second rig i have an aw9d-max/e4300 running on air with a tt big type 120vx. the e4300 definitely tends to run hotter. have not tried coretemp 095 here as this version crashes my ab9quadgt/e6400 system. seems you are using coretemp 095 successfully. can you post screenshots or just the different readings (temp, dts, tjunction, cpuid, revision, processor) of coretemp 094 and 095? in coretemp 094 temps on the e4300 are going up to 70c. this would translate to dts readings of 15c! if i'm right coretemp 95 should read about 85c in the same situation.
also what voltage do use on the e4300?
haha...your cooling is listed right there in your sig...I was just too tired to nitice I guess.Quote:
Originally Posted by fgw
These screenshots are at idle, 60% TAT load, and 100% TAT load.
I'm at stock voltage, 1.325-V
http://img393.imageshack.us/img393/2549/15515518gp3.jpg
http://img393.imageshack.us/img393/3771/14286848fv4.jpg
http://img136.imageshack.us/img136/8918/20453105lt5.jpg
Obviously, all of those who know the logic behind this mechanism will use the Delta temp and not the absolute temp.
But still, getting closer to 'the truth' behind this is intriguing to say the least. I'm especially curious, why did CoreTemp v0.95 decided to change L2 rev chips Tjunction temp to 100c? Where was this logic derived from? It doesn't make much sense because as we can see it seems that L2 chips are much much hotter. If it's a newer revision, going through the same manufactoring process, why is it significally hotter? I can understand ~5c. but not 15c.
To match the results displayed via TAT. Obviously TAT is assuming a Tjunction_max of 100.
thanks for your screenshots. can't use tat on my board and coretemp 0.95 doesn't work either ...Quote:
Originally Posted by joebuffalo
from looking at your screenshots: thats what i have expected.
guess the assumption here is, tjunction could be either 85c or 100c and as 85c was obviously to low it must have been 100c then!Quote:
Originally Posted by GGuyZ
btw. from reading your post at the coretemp forum i have seen you also followed the thread at the intel software network forum...
the point, as we all know in the meantime, is tat was designed for mobile processors only! the use on desktop processors might produce results that look right but nobody knows if they are. i really doubt it.Quote:
Originally Posted by joebuffalo
from all what i have read on this so far:
- the decision if 85c or 100c are to be used, based on a single bit in a msr, is not valid for desktop processors and thus wrong.
- even on desktop processors the temp is not exactly 85c or 100c. its just some where near this point.
- this temp is calibrated on a per chip basis and thus different from die to die.
- there is no way to read this temperature by software
- the only reliable way is to use the dts value directly
although not that precise you can use a monitoring program that's reading the thermal diode. comparing this readings to coretemp readings while the processor is forced into throttling. this could give an idea about the value of tjunction. in fact its not tjunction, its the temp where thermal control circuit gets activated, but thats a different story. at least you can figure out if its near 85c or near 100c ...
i tried this on my e6400. throttling kicked in at coretemp readings near 85c. don't remember the correct value. might have been 86c or 87c, but it definitely was not 100c!
Dude ran his e4300 up to 97-C (according to TAT) before he encountered throttling.
http://forumz.tomshardware.com/hardw...ict230942.html
Obviously TAT is GREAT for putting max load on CPUs. But it is terrible for reading temperatures because it was not made for desktops and we have no idea what Tj_max it is assuming when it calculates an absolute temperature. Long live DTS!
ted3: Sorry man, thats not throttling.
When I brought my E6400 up to 85C it was definitely throttling. On the Intel C2D there are two types of throttling.
http://www.intel.com/design/processo...als/253668.pdf
Here's a quote from page 13-5 of the Intel® 64 and IA-32 Architectures Software Developer's Manual, Vol. 3A:
"One mode modulates the clock duty cycle; the second mode changes the processor’s frequency. Both modes are used to control the core temperature of the processor."
When a C2D processor first starts to approach Tmax the duty cycle will be reduced from 100% to 87.5%, 75% and continuing down to 12.5% in 12.5% increments. If the temperature of the processor still can't be controlled then the second mode kicks in which reduces the processor frequency (MHz) like you experienced. The first "duty cycle" throttling happens approximately 3C or 4C before Tmax.
My testing has shown that CoreTemp 0.95 which uses a Tjunction of 100C for the E4300 is reporting the temperature correctly.
Rather than take a processor up to the boiling point I decided to do the opposite. I set out to try and run the processor as cool as possible.
To do this I dropped the FSB to 266 MHz ( 200 MHz for the E4300 ), I dropped the multi to 6X and then I also dropped the core voltage down to 1.175 volts. I booted up and set the Intel CPU fan at full speed to cool the processor as much as possible.
At idle I was able to get my E6400 down to 2C - 3C above ambient temperature which makes sense. A C2D puts out minimal heat at idle and even the OEM cooler is sufficient to dissipate that heat.
When I did a similar test on an E4300, CoreTemp 0.94 was reporting the core temperature significantly below ambient temperature which is impossible. An air cooled processor can't be running cooler than the surrounding air so this is a sign that CoreTemp 0.94 was reading too low.
By this test, the 15C correction introduced with CoreTemp 0.95 is correct for the E4300.
It would be interesting to see if anyone else can duplicate these numbers. This is the best and safest way I've found so far to prove that a software monitoring program is wrong.
CoreTemp 0.95 seems to be the most accurate program to date. If you don't believe the absolute value reported then just switch it to "Show Delta to Tjunction temp". I like to leave at least 10C to 15C of headroom to Tmax for maximum performance and stability.
The Tjmax for nay core 2 chip is not necessarily 85 or 100 exactly. It is calibrated for each chip at the factory. That's why the DTS reading is so damn awesome.
And I *think* you weren't throttling. In the Intel docs, it states that the DTS reading is the number of degrees between the current core temp and TCC (throttling). So unless you see a DTS of 0 in CoreTemp 0.95 you shouldn't be throttling. I think. (And since you said you were at 85 degrees, that's somthing like 10 or 20 degrees DTS) Maybe I misunderstood something.
I supposed you have to ask yourself what's more believable, allendale core CPUs (E4300 or L2 E63/6400) that idle at or below ambient temperature or that the "reference" Tjunction value for them needs a +15C adjustment?Quote:
Originally Posted by GGuyZ
Anyway, isn't it just a reference value which gives a far better idea of CPU temperatures than we've ever had before to better maintain optimal performance when overclocking? Who really cares if it's 100% accurate?
Is there any documentation from Intel or any evidence from other users to support that? I'm not saying it's not true. I'm just interested like everyone else in what's really going on.Quote:
Originally Posted by joebuffalo
For my E6400 Revision B2, CoreTemp uses this formula:
reported temp = 85 - DTS
CoreTemp reports 85C when DTS equals zero.
During testing, TAT first started to report, "Thermal Monitor Active" in red for Core0 when DTS was at 2 so CoreTemp was reporting 83C. At this point the reported MHz is not yet reduced but the performance of the processor starts getting reduced internally to try and control the temps. CPUz will still be reporting full MHz but performance is reduced.
If the temperature of the processor can still not be controlled using this first thermal throttling technique, then the processor MHz will also be reduced. If the temperature still can't be controlled then finally the "catastrophic shutdown detector" is enabled and the processor shuts down.
Both methods of throttling will result in reduced performance for your processor. At stage 1, the reported MHz might still show your CPU at full speed but performance is already being reduced.
The reason Tjunction or Tmax was raised from 85C to 100C for the E4300 isn't because the E4300 puts out any more heat or runs hotter than previous C2D chips. A chip built on the same manufacturing process, being supplied the same voltage and running at the same frequency is going to put out pretty much the same heat as previous C2D processors.Quote:
Originally Posted by GGuyZ
Intel raised the maximum so this chip can run 15C hotter before thermal throttling will take place.
The E4300 is designed as a budget chip which will be used in small budget computers that typically have poor air flow and system cooling. This chip gives computer manufacturers more head room to design a small computer without having to worry about the processor hitting the thermal throttle and slowing down performance.
Mea culpa. Sometimes I forget that not everybody has an e4300.Quote:
Originally Posted by unclewebb
I *thought* I read that in the spec sheets somewhere, but I can't seem to find it in my notes. Maybe I just read it on a forum? I did find this:Quote:
Originally Posted by unclewebb
http://documents.irevues.inist.fr/bi...79/1/TMI23.pdf
"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."
Which sort implies what I claimed, but certainly doesn't say it clearly. Either way, the paper is a good read.
I read the above paragraph and of course came to the opposite conclusion.Quote:
Originally Posted by joebuffalo
I think if Intel is making a batch of processors with a Tjmax of 85C then they calibrate the DTS during manufacturing so that it reads 0 when the hottest point in the core is at exactly 85C. Same thing for the E4300 at 100C. This happens at the Filtering and Post Processing stage in the diagram where an offset can be added to the DTS reading to correct for any variation in the digital sensors.
To me it makes no sense that Intel would manufacture a batch of processors and then bin them based on what temp they should be able to run at.
"This one looks like it can run at 85C so we'll set Tjmax=85 and then the next one gets set to 87 or 90 or ....."
It makes a lot more sense that Intel determines for long term reliability and for stability that the first generation of C2D processors can run fine at up to 85C so they set that value to every processor to avoid excessive warranty claims. With further testing and with improved manufacturing they feel that their second generation of processors built on the Allendale core can run reliably up to 100C so they bump Tjmax up 15C.
Whether my interpretation or yours is right isn't too important. CoreTemp 0.95 tells you the DTS reading directly and references that to either 85C or 100C depending on your processor. It then calculates a core temperature based on one of those two reference points.
My processing power first gets reduced when DTS=2. If you're not overclocked then you should be able to continue and get to DTS=0 without any loss in stability. When fully overclocked, I found that the length of time that Orthos could run without any errors decreased when DTS dropped below about 13. That's the important number for my computer. I have great long term stability at DTS=15 and not so great when DTS=10.
Thanks for that article. Every little bit of information helps.
joebuffalo, might have referenced the following paragraph in the Thermal and Mechanical Design Guidelines to be found here:Quote:
Originally Posted by unclewebb
http://www.intel.com/design/processo...nex/313685.htm
4.2.8 THERMTRIP# Signal
The temperature where the THERMTRIP# signal goes active is individually calibrated during manufacturing. The temperature where THERMTRIP# goes active is roughly parallel to the thermal profile and greater than the PROCHOT# activation temperature. Once configured, the temperature at
which the THERMTRIP# signal is asserted is neither re-configurable nor accessible to the system.
i would interpret this in the same way. individually calibrated during manufacturing let me assume this temperature is different from one processor to the other.
also i have read, but unfortunately don't remember where: "this thermtrip value is calibrated during manufacturing on a per chip basis by burning some shunts on the processor and may vary from die to die."
another interesting read on this issue is the thread on the intel software network forum:
http://softwarecommunity.intel.com/i.../30222546.aspx
look at the post before the last one:
...Note Tj is not a fixed value and the IA32_TEMPERATURE_TARGET[15:8] value can vary from part to part. Tj is also not software readable....
...Some steppings of the mobile Intel® Core™2 processor do indicate Tj to be approximately 85 or 100 via a single bit in the EXT_CONFIG register (msr 0EEh) but desktop, workstation and server processors do not....
this two modes (thermal monitor and thermal monitor 2) are not kicking in in sequence. you can select in bios, or trough software by writing to some registers, which thermal monitor mode you want to use. both start at the same temperature at prochot#.Quote:
Originally Posted by unclewebb
and yes, thermal monitor 2 is the more powerful one as not only fsb but also vcore gets reduced.
Thanks fgw & joebuffalo for the additional info. Looks like I got some more reading to do!
It certainly looks like Tj_max is higher on the L2's...do we agree on this?
So my new question: Is it *wise* to run yourn e4300 at the same DTS as an e6600? Just because the Tj_max was raised, does that mean we *should* be running our L2 processors at a higher absolute temperature? Obviously we can...but should we?
i would say it's always good to keep temps as low as possible. besides that i would not hesitate to increase vcore, and temps obviously too, until dts approaches 0c. intel would not have changed this tjmax if reliability cant be maintained at this temps.Quote:
Originally Posted by joebuffalo
anyway, to keep some safety margin would be a good idea for sure. i personally would keep this margin in a range of 10c to 15c.
as vcore is increased, temps need to be decreased in order to keep electromigration and thus reliability under control. so i would add another 20c to this safety margin.
for coretemp, this leads to a dts reading of about 35c or
i know there is some talks about this issue (electromigration) going on in various threads so i wont comment on that right now. found some documents explaining this and will start a thread on this later on.
- a temp reading of about 50c if your tjunction in coretemp is 85c and to
- a temp reading of about 65c if your tjunction in coretemp is 100c.
imho, that's a HUGE DTS.
A very wise (and conservative) man wrote this Core 2 Temperature Guide:
http://forumz.tomshardware.com/hardw...ict221745.html
and he seems to think that 65-C is AOK for the Tj_max = 85 systems. That's a DTS of 20. Right now my DTS is ~30 with my e4300 at 2.7-Ghz (stock 1.325-V) topped with a Scythe Ninja / 1300 RPM Yate Loon fan and AS5.
So I'd say a DTS of 30 leaves a LOT of headroom. A DTS of ~20 seems reasonable based on the opinions in the thread above.
I'm still just not sure that we should be running L2's at the same DTS as the older Core 2 CPUs. Should we run the L2's x-degrees hotter just because Tj_max went up x-degrees. (That's why I am keeping my DTS at ~30 for now)
BUMP
r we reachin on any conclusion ???
i would not rely too much on this post over at the thg forums. there are a lot of misinterpretations in it!Quote:
Originally Posted by joebuffalo
lets start with the things you can confirm by looking at intel datasheets:
Datasheet
http://www.intel.com/design/processo...hts/313278.htm
Thermal and Mechanical Design Guidelines
http://www.intel.com/design/processo...nex/313685.htm
yes, there are more than one sensors measuring temperatures
intel defines tcase at the temperature measured on top of the ihs and at the center of the ihs.
- one thermal diode located on the processor die
- two digital temperature sensors within each core on c2d
- four digital temperature sensors within each core on quad
afik, bios or software is not displaying tcase! the temperature displayed there is simply the processor temperature measured via the thermal diode. the thermal diode as implemented by intel is delivering a voltage proportional to processor temperature. the software using this signal has to calibrate this readings and convert it to a temperature. as different software, or bios, is calibrating this readings differently, you get different temperatures but by no way tcase as described above.
the digital temperature sensors on the other hand, are located directly within the cores near the hottest places. this sensor has a smaller footprint and thus can be located easier within the core. the reading, as opposed to the thermal diode, is not a voltage! digital temperature sensors convert the temperature directly into a binary value (dts reading) and store it in a register within the processor thus eliminating the need of calibrating this sensor readings.
the problem here is, this dts reading is not absolute. its a relative temperature to the thermal control circuit activation temperature (prochot#). as this thermal control circuit activation temperature is calibrated during manufacturing on a per part basis and is not read by software it is impossible to convert dts readings into an absolute temperature.
on mobile processors tjunction as a reference temperature instead of thermal control circuit activation temperature. also, there were just two possible tjunction values used on mobile processors in the past (don't know intel plans on future mobile processors). on this mobile processors, there is a bit in a register which can be read to check if tjunction is at 85c or if it is at 100c! absolute temperature can now simply calculated by substracting dts reading from tjunction. thats how coretemp, and i assume all other programs using digital temperature sensors readings, calculate absolute temperatures.
using this method on desktop or server processors might result in a temperature reading that look right, but this does not mean it is correct.
there is only one correct temperature reading on intel core technology processors: relative temperature (dts reading) as introduced incoretemp 0.95
everything else, besides mobile processors as discussed above, is speculation!
and so is most of the following:
added comments to some of them although almost all are either questionable or obvious ...
- Tcase + 15c = Tjunction its more like: dts reading + 15c = thermal control cicuit activation temperature
- Thermal Case Temperatures of 60c is hot, 55c is warm, and 50c is safe. well, this might be true, but there is no way to measure tcase besides a temp probe on the ihs! do you use one? i don't.
- The difference between Tcase (BIOS, Motherboard Utilities and SpeedFan: CPU or Temp X) and Tjunction (TAT and SpeedFan: Core 0 / Core 1) is Tcase + 15c = Tjunction
- Vcore should not exceed ~ 1.5v.
- Tjunction is always ~ 15c higher than Tcase.
- Tcase is always higher than Ambient. as any temp as long as you are on air or water ...
- Tcase Idle should be ~ 1 to 15c higher than Ambient.
- Tjunction Idle should be ~ 15 to 30c higher than Ambient.
- Tcase Load should not exceed ~ 55c with TAT @ 100% Load. again, how is it measured?
- Tjunction Load should not exceed ~ 70c with TAT @ 100% Load.
- Idle to Load Delta should not exceed ~ 25c.
- Tjunction Results are Hottest Core Idle and Load.
- Vcore will typically sag ~ .025 volts under Load. depends on motherboard
- Any hardware and / or software may misreport Tcase and / or Tjunction temps.
- 965 chipsets may misreport Tcase and Tjunction temperatures with +/-15c offsets. the chipset is not involved at all - all sensors are within the cpu. well, calibration of thermal diode is done in bios
- If TAT will not run, then Orthos Priority 9 Small FFT’s simulates 88% of TAT ~ 5c lower.
- C2D’s manufactured with concave Integrated Heat Spreaders may report high Deltas and temps. true
- An improperly seated CPU cooler is the leading cause of abnormally high temperatures. also true, but again - no surprise here
I agree with a lot of what you said there.
Although I think the mobo does come into play when talking about Tcase (keep in mind he is not defining Tcase the same way Intel is...is is talking about the thermal diode output) because the mobo is where the thermal diode reading is converted into a temperature reading.
I didn't post his link because I think that thread is correct. In fact I disagree with a lot of it...that's how I wound up here on the DTS bandwagon. My point was just that he recommends a DTS of 20 (doesn't actually SAY that, but you and I know that is the jist of it) and I think he is pretty conservative (maybe it's because I've read his opinions on many overclocks) when it comes to temperatures.
I think your 30-degree DTS is VERY safe. Too safe for a bunch of overclockers...imho.
you are right! but i mentioned this 30c by two reasons:Quote:
Originally Posted by joebuffalo
- electromigration: to maintain the same reliability, temperature has to be decreased by 20c when current density gets doubled. i know, increasing vcore from 1.28v up to 1.50v does not result in doubling the current density, but the scale is logarithmic, so in my case temps might be decreased by 17c or may be 15c!
- simply the fact, that my watercooling system is able to maintain this sort of safety margin ...;)
I agree with the above statement 100% but.......Quote:
Originally Posted by fgw
I still think that CoreTemp 0.95 which uses either a fixed 85C or 100C Tjunction value in its calculation results in a pretty accurate absolute temperature for the desktop processors.
I decided to come up with a simple test so users can determine if the absolute temperatures reported by CoreTemp are valid or not.
On my E6400, revision B2, CoreTemp 0.94, CoreTemp 0.95 and SpeedFan 4.32 all report the same temps. For this test I used SpeedFan for its graphing capabilities.
The goal is to run your processor as cool as possible. Start by opening your case. Next lower the FSB to 200 MHz, lock the cpu multiplier in the bios at 6 and reduce the core voltage. Setting core voltage to 1.200 volts or less is adequate. With my P5B Deluxe I was able to get the core down to 1.104 volts as reported by CPUz.
You can do this with any Core2Duo so this test is consistent no matter what processor you have.
I believe that when you run an air cooled processor at reduced speed and voltage in an open case, the core temperature will start to approach the ambient temperature. I used SpeedFan to keep the cpu fan at its maximum.
With a room temperature of 18C as measured with a consumer grade digital house thermometer, I ended up with a reported core temperature of 17C during this test.
http://img207.imageshack.us/img207/6513/testvd4.png
In theory with air cooling you shouldn't be able to get lower than ambient temperature but if you keep in mind that both values are integer values and are at best only accurate to +/- 0.5 degrees and that my $20 Radio Shack thermometer is far from perfect then I think my results confirm that:
An air cooled C2D at 1200 MHz and 1.1 volts will put out so little heat at idle that the core temperature and the ambient temperature will be very close to equal.
For my E6400, the CoreTemp / SpeedFan assumed Tjunction value of 85C, seems to produce a very accurate absolute temperature value.
This test can be used by anyone with any Core2Duo processor to at least give them an idea if their temperature monitoring software is in the ball park or if it's totally out to lunch.
Fair enough. But riddle me this, enclewebb:
What good is the absolute temperature? How do you know what is a safe absolute temperature? That's the beauty of the DTS, it tells you the 'Degrees To oh Shoot'
Hey, just want to get some input from you guys about my CPU temps. I was previously using the stock Intel cooler that came with my QX6700... but after a bunch of temp readings that were confusing, I took the safe route and assumed the higher temp readings were the accurate ones. Below are screenshots from TAT/CoreTemp/Everest from the time I was using the stock HSF:
http://www.waddekao.com/files/biatch0/everest.jpg
http://www.waddekao.com/files/biatch...e-coretemp.jpg
And here's a screenshot of those after I installed the new ASUS Silent Square Pro:
http://www.waddekao.com/files/biatch0/allin1.jpg
The temps I'm getting are still a little on the high side which worries me... anyone with an aircooled QX6600/6700 with temp screenshots?
Users seem to like knowing the absolute temperature of their cpu, even if that number isn't 100% accurate.Quote:
Originally Posted by joebuffalo
Using my testing method you can at least determine if your Tjunction is about 85C or about 100C and which version of CoreTemp is reporting your absolute temperature closest to reality.
Going by DTS is great in theory but already there are discussions of what is a good DTS number to shoot for and a 101 qualifiers like whether you are overclocked or over volted and by how much, etc., etc. I've already discovered that if you are at default MHz and voltage that you can run reliably at a higher core temperature than if you're fully overclocked which makes sense.
People have never been able to agree on a safe absolute core temperature any more than they will ever be able to agree on a safe DTS value.
My E6400 with an approximate Tjunction of 85C showed Orthos stability started to decline when DTS went below 15C and declined further when it got to 10C. I have absolutely no idea whether those results will apply to an E4300 which has a Tjunction of 100C. It's possible that a well overclocked C2D looses stability when its absolute core temperature exceeds 70C to 75C regardless of what Tjunction Intel has rated it at.
Hopefully some E4300 owners can shed some more light on this topic by doing their own testing.
biatch0: You didn't mention whether those are idle temps or if you are running something like Orthos at full load.
If those are idle temps then I think you should look at re-mounting your cooler.
If those temps are while running Orthos then temps in the low 60C range with all 4 cores loaded at 3000 MHz looks pretty good to me. The Quads put out more heat and are going to run hotter at the same load and same frequency compared to a Core2Duo.
thats true! its also true for watercooled systems, except its not ambient temp but water temp that can't be beaten!Quote:
Originally Posted by unclewebb
would not mind if temps are off by a few degrees, but if the processor runs at stock, or even below that and you get core temps 10c or more below ambient than tjunction in coretemp is wrong and thus your absolute core temps!
yes, your simple test can quickly verify if coretemp or whatever software used, gets the reference temp (tjunction in coretemp) correctly!
I somehow have the feeling that CoreTemp 0.95 does not work "correct" for all E4300. I built 2 E4300 rigs last week using the Infinity and the idle temp at stock volts/stock clock was 42-46C on both rigs. So I am having the feeling thats not the real temp for one of the best air coolers and a C2D at stock. With 1.34V real I had 80C according to coretemp at 3150Mhz after 19hours of Orthos. Those temps dont seem to be right to me. 15C less than that sounds more like it. Unfortunately I have only remote access to those rigs, so I cant test much from here :/
Have you read this thread?Quote:
Originally Posted by Fr3ak
Most of it.
From what I understood, 0.94 reads 15C to low for the E4300, so it was changed in 0.95 which reads a 15C higher temp.
Now what if the 15C issue is not working for all E4300 batches?
That's what I've found as well. They seem to come with either a TjMax of 85C or 100C and no software so far can tell the difference.Quote:
Originally Posted by Fr3ak
If it guesses wrong your reported temps will be wrong by 15C. Lucky a smart guy figured out a possible way to determine which one is right. :D
The only thing I've found is it might be related to the manufacturing date code. I found an early E4300 with date code L640 which seemed to have a 100C TjMax and one with a date code of L644 which had a TjMax of 85C. Between week 40 and week 44 of 2006 is anyone's guess.
Nobody knows what the Tjmax for Core2 Duo desktop processors is. As such, it is impossible to determine the absolute core temperature of the processor.
I think your method, unclewebb, although logical, is flawed. You are still *assuming* many things to make you calculation.
You are also assuming that there is no thermal gradient within the processor. You assume that Tjunction and Tcase are equal.
You assume that the air inside your case is the same temperature as the air outside the case.
You are assuming that Tjmax is either 85 or 100.
I see what you are shooting for. But you method is based on a LOT of assumptions that I don't see the point. Why do you need to know the absolute temp, based on assumptions, when you already know the relative temp with certainty?
CoreTemp 0.95 works PERFECTLY with any Core2 processor because it measures, and can be configured to report, the DTS...which is all you need be concerned with.
joebuffalo,
second that!
You mean like this?Quote:
Originally Posted by joebuffalo
http://slidog.bigblog.com.au/data/2/...0423202957.png
It would be seriously great if it is. :)
It just seems like it's based on the same Tjunction value set by the software, which is the cause of this argument, but it just reads in reverse :confused: :)
jumping in here as i requested this feature (show delta to tjunction temp) over at the coretemp development forum.Quote:
Originally Posted by SLi_dog
anyway, YES this is the feature!
all temp monitoring software which is using dts (digital thermal sensor) is reading the temperature from a register within the processor. this register holds the plain dts value showing the temperature offset to
- tjunction temperature for mobile processors
- thermal control circuit (tcc) activation temperature for desktop and server processors
absolute core temperatures are simply calculated by the following formula:
core temperature = tjunction - dts or core temperature = tcc - dts
it doesn't really matter if you call it tjunction or tcc as in both cases this temperature is just an assumption made by the writer of the monitoring software. the value used in the formula counts, not the name ...
accuracy depends on the correct chosen value for tjunction or tcc which is obvious by looking at the above formula. as intel does NOT make this values available to public nor is this value readable by software, software developers have to guess what value should be used for tjunction.
thats the difference in coretemp 94 and coretemp95! both versions of coretemp simply use different values for tjunction, either 85c or 100c. thats why readings in coretemp might be off by 15c on certain processors.
using the delta to tjunction temp instead, displays plain dts readings without conversion to an absolute temperature value thus being completely independent from probably wrong selection of tjunction value in monitoring software. using this feature in coretemp makes you completely nonindependent from tjunction and gives correct values on ALL processors supporting dts.
this delta to tjunction temp just says how many degrees is the processor away from tcc activation (throttling) and thus looks reverse to regular coretemp readings: large dts means cool processor, small dts means hot processor!
the last question here: what is a save dts value?
well as with regular coretemp readings this depends on the environment your processor is running in. my very personal rule is as follows:
this assumptions take into account that higher vcore results in higher current and thus in higher current density which besides temperature is the most responsible parameter for reliability or failures due to electromigration. reducing operating temperatures maintains reliability even if current density (vcore) is raised.
- running on high vcore, which to me is everything above 1.5v, i would try to keep dts above 30c. (this translates to about 55c in coretemp94)
- on lower vcore, a dts value above 15c should be fine and easy achievable. (70c in coretemp94)
the general rule is roughly: decrease temps by at least 20c for every current density increase of 100%! yes, there is some safety margin in my personal rules.
again, this is my very personal opinion gathered from reading through a lot of documents on this issues ...
joebuffalo: You've brought up some valid points. I'm going to do some more testing and hopefully in a day or two I might have some more information for you.
I was just testing RightMark CPU Clock Utility. Version 2.25 is now capable of monitoring core temperatures of the Core2Duo.
http://www.softpedia.com/progDownloa...oad-18249.html
This utility seems to track very closely the absolute temperatures reported by Tat and CoreTemp from ambient to over 80C. It also shows you when TM1 and TM2 throttling become activated and by what percent.
The interesting thing is that it is the first utility I've seen for the C2D that displays core temperatures with a resolution of 0.2 degrees.
ie. 40.0, 40.2, 40.4, 40.6, 40.8, 41.0
Edit: Upon further testing I've discovered that this program averages the previous 5 temperature values which gives the look of better temperature resolution but it is still using the same Intel documented DTS integer value and guessing at a Tjunction value like every other program.
I guess that's my question though, is it reporting the actual DTS sensor and its approach to throttling or is it just calculating the readings in an alternate method based on the application determined Tjunction?Quote:
Originally Posted by fgw
I really have a limited idea of how these sensors work and/or I may not be configuring it right however I'm wondering if it would simply read a different "delta to Tjunction" value if I changed to a CPU that CoreTemp believes has an 85C Tjunction value? :confused:
Cheers :toast: :)
DTS is read *directly* from a CPU register. No calculations are involved. No assumptions are made. It is the ONLY temperature reading that is reported directly from the CPU.
EVERY software tool that says it can report an absolute core temperature reads the DTS (they all read the exact same DTS value), assumes a tjmax, and calculates an absolute temperature.
So.......if it was somehow possible to change the CoreTemp Tjunction value from 100C to 85C, the Delta to Tjunction wouldn't end up being 15C lower as it's purely reporting the DTS value? :confused:Quote:
Originally Posted by joebuffalo
If not, how is it different to CoreTemp reporting based on an assumed Tjunction value?
Just trying to understand this, thanks for the patience :)
correct!Quote:
Originally Posted by SLi_dog
the point here is, you simply don't know if the assumed tjunction value which is used in temperature calculation is correct or not.Quote:
If not, how is it different to CoreTemp reporting based on an assumed Tjunction value?
e.g. if you have a dts (Delta to Tjunction) of 30c you get a core temperature displayed in coretemp of either 55c or 70c depending on tjunction value assumed by coretemp for your processor. is it now 55c or 70c your cores are running at?
on the other hand, if you are looking at plain dts (Delta to Tjunction) you can see you are still 30c away from throttling and this holds true regardless what tjunction value was selected by coretemp as no calculations and assumptions are involved.
btw. this is the same for all other programs using dts to read core temperatures. afik, coretemp is the only program giving you the ability to display dts (Delta to Tjunction) directly and thus is the preferred choice!
But don't you find it strange that the "Delta to Tjunction" throttle point with the quad core co-incides exactly with the software written Tjunction value of 100C? :confused:Quote:
Originally Posted by fgw
I guess I'm still not convinced but I'll bow to your knowledge guys. Thanks for the help and patience :toast: :toast: