Real Temp - New temp program for Intel Core processors

[DGill]

Originally Posted by jarthel

what's the advantages of this software versus coretemp? thank you

From what I understand, reading through this post is it seems the CPU sensor is like a mercury thermometer without a scale. To calibrate a mercury thermometer it is put in boiling water. For the CPU sensor, Intel inform us that for a E8400 the point that the cpu shuts down is called tjmax and that value is 100C ( + or - 5C ?)

To complete the calibration of a mercury thermometer it is put in ice water. Apparently there is no equivalent reference point for the CPU.

So it seems most programs assume a linear decrease of sensor voltage with temperature from tjmax. I believe Unclewebb does not make this assumption and uses a calibration curve that is based on actual measurements so RealTemp is potentially more accurate than programs such as Coretemp.

[rge]

I know we had all brought this up before at one time or another, but I am thinking all cpus have a roughly 26-30C difference between Tcase max and Tjmax, see the knowns below. Only one cpu unclewebb tested deviated from that, and that cpu came in both 60 and 70 range tcasemax, and I am thinking the factory worker that day said, oh ****, what stepping was that today? It would make sense for the gradients to be constant, in fact it would not make sense for them not to be.

Also you can see intel is clearly rounding tjmax numbers, compare those to actual tcase max. Intel does not care about absolute tjmax, but tcase they calculate to tenth decimal.

Processor--power(W)--Tcase max--Casing IR(idle)--Tjmax----absolute temps at tjmax (+/- few C according to intel)
E7x00-------65---------74------------------------------100
E8x00-------65---------72.4-----------95--------------100
Q9650-------95---------71.4---------------------------100
Q9000-------95---------71-----------------------------100
QX9650----130---------64.5----------------------------95
QX9770----136---------55.5----------------------------85

Q6600 GO--95----------71-------------95-------------100?
Q6600 B3 -105---------62.2-----------85--------------90?
E6850------65----------72-------------95-------------100?
E6700------65----------60.1-----------85?-------------90?
E6600------65----------60.1-----------85--------------90?

QX6800 GO-130--------64.5-----------90?-------------95?
(compare to QX9650 with known tjmax)

QX6800 B3-130--------54.8-----------80?-------------85?
(compare to QX9770)

E4400 L2--65-----------61.4----------85---------------90?
E4400 M0-65-----------73------IRx1 85 ? intel employee thinking it was L2 stepping day, or fluke?

And the formula from intel, suggests there is a constant gradient from tjmax to tcase, as now strongly suggested by same tjmax on both E8x00 and E7x00 despite one solder attach, the other adhesive attach and by quads proven to have same gradient tjmax to tcasemax as duo's, and the slight variance in absolute temps at tjmax intel just rounds out.

[JohnZS]

I like your thinking rge
It stands to reason that there would be a correlation between Tcase and TjMax.

Unclewebb
2.75 rocks
This screenshot was taken after heavy stresstesting on IntelBurnTest 1.5.1
Now, the idle temps are more or less the same (which is good), but also the load temps are all within 5C of each other.
I am not quite sure how Reltemp is reporting a minimum of 19C on one core though



2.75 is definitely an improvement over previous versions with my Extreme Sensors

Thanks
John

[WaterFlex]

JohnZS nice temps dude

[unclewebb]

JohnZS: that minimum might have been recorded if you were changing calibration factors just before starting your test or it might just be another random number from your bizarre sensors. Thanks to Intel, I now have someone / something to blame no matter what RealTemp says. It's the crappy sensors!

what's the advantages of this software versus coretemp?

Now that all programs should be using the same TjMax for 45nm, there shouldn't be that much of a difference for most processors. The only big advantage that RealTemp has is that it lets you individually calibrate each sensor. CoreTemp is useless for processors like the one JohnZS has. CoreTemp offers no adjustability so it will report his center two cores 15C different from each other even though their temperature is almost exactly the same. CoreTemp will also report my E8400 too hot at idle.

Page 8 of the Intel presentation at IDF shows you that the slope error these sensors have can grow to be a significant amount at low temperatures. So far, RealTemp is the only program that gives you a way to try and correct for this. It's not perfect but it's better than nothing.

[jason4207]

UncleWeb,

Now that we are assuming an ~5*C gradient at load should we also assume that at idle? Instead of calibrating so that idle temps are 4-5*C above ambient for dual-core (and 6-7*C for quad) should we be using different assumed values to calibrate?

[colt1911]

UncleWeb, I've been using Real Temp ever since I discovered the program here on this forum. Thanks for a good job. What do you recommend setting the Tjmax on the Q9450? At the moment I have it set to 95.

[rge]

Originally Posted by jason4207

UncleWeb,

,Now that we are assuming an ~5*C gradient at load should we also assume that at idle? Instead of calibrating so that idle temps are 4-5*C above ambient for dual-core (and 6-7*C for quad) should we be using different assumed values to calibrate?

I have not put this pic up before but i just sent to unclewebb. It is testing of a pentium northwood which has a higher gradient than 65nm (65nm has more copper bands in silicon die and better die attach, etc). But it illustrates the point of idle vs load. It is from yang et al, who has done some testing for intel as well.

Ignore the solid grey top lines, it is software estimating the die temp of a pentium northwood by estimating power usage/leakage, and then converting to temps.

The red scribble is mine.
-Ambient at idle = bottom red arrow (bottom broken line).
-Thermocouple in IHS at idle = middle red arrow (middle broken line labeled spreader by authors, temp was double checked with FLIR for accuracy).
-CPU diode between cores at idle = the top red arrow (top broken line labeled On-die by authors)
-There is no DTS sensor. The solid grey lines above diode is software guessing hot spot temps mathematically. At idle DTS same temp as cpu diode (confirmed on 65nm intel testing at idle, there is no offset between those at idle)

At idle (blowing up bitmap with ruler)
-IHS is 3.5-4C higher than ambient.
-The cpu diode (and DTS if had one) is 3C higher than IHS (compare this with intels 5C gradient IHS to tjmax).
-So the cpu diode (and the DTS on die) are 6-7C higher than ambient, at stock clock, stock volts, with stock heatsink. (But northwood is hot cpu, less copper bands on die, less conductivity, worse die attach. But power density is higher on 45nm so, again left to guess for 45/65, but that gives you a ballpark.)

At load
-5-7C difference between IHS (spreader) and cpu diode (on die), and that is constant on load for most programs.
-There is no DTS sensor, each grey solid line are software guessing hotspots in different die locations.. DTLB, L1, etc, you can see the varying temp gradients. (But intel did actual die sensor measurements on 65nm, and found lower gradients, but also 65nm would have lower gradients because of improvements and increased copper bands.

So at idle with EIST/speedstep enabled, or undervolted, I would still be using 5-7C above ambient for stock cooling. For different cooling computronix had a pretty good formula that worked for mine. On water I calibrated my cpu diode 3C above water temp, which came to 3C above IR reading at DTS=0, at idle, underclocked...close enough.

[jason4207]

Originally Posted by rge

I have not put this pic up before but i just sent to unclewebb. It is testing of a pentium northwood which has a higher gradient than 65nm (65nm has more copper bands in silicon die and better die attach, etc). But it illustrates the point of idle vs load. It is from yang et al, who has done some testing for intel as well.

Ignore the solid grey top lines, it is software estimating the die temp of a pentium northwood by estimating power usage/leakage, and then converting to temps.

The red scribble is mine.
-Ambient at idle = bottom red arrow (bottom broken line).
-Thermocouple in IHS at idle = middle red arrow (middle broken line labeled spreader by authors, temp was double checked with FLIR for accuracy).
-CPU diode between cores at idle = the top red arrow (top broken line labeled On-die by authors)
-There is no DTS sensor. The solid grey lines above diode is software guessing hot spot temps mathematically. At idle DTS same temp as cpu diode (confirmed on 65nm intel testing at idle, there is no offset between those at idle)

At idle (blowing up bitmap with ruler)
-IHS is 3.5-4C higher than ambient.
-The cpu diode (and DTS if had one) is 3C higher than IHS (compare this with intels 5C gradient IHS to tjmax).
-So the cpu diode (and the DTS on die) are 6-7C higher than ambient, at stock clock, stock volts, with stock heatsink. (But northwood is hot cpu, less copper bands on die, less conductivity, worse die attach. But power density is higher on 45nm so, again left to guess for 45/65, but that gives you a ballpark.)

At load
-5-7C difference between IHS (spreader) and cpu diode (on die), and that is constant on load for most programs.
-There is no DTS sensor, each grey solid line are software guessing hotspots in different die locations.. DTLB, L1, etc, you can see the varying temp gradients. (But intel did actual die sensor measurements on 65nm, and found lower gradients, but also 65nm would have lower gradients because of improvements and increased copper bands.

So at idle with EIST/speedstep enabled, or undervolted, I would still be using 5-7C above ambient for stock cooling. For different cooling computronix had a pretty good formula that worked for mine. On water I calibrated my cpu diode 3C above water temp, which came to 3C above IR reading at DTS=0, at idle, underclocked...close enough.

Good info, but I'm still left guessing as to how (exactly) I should calibrate my CPU.

Right now on my 45nm Quad I have my cores adjusted to 5*C above ambient while idle at 200x6=1.2GHz 1.05v on an U120E w/ a 110CFM Panaflo at 100% in 25*C ambient. I had to bring 1 core up, and the other 3 down.

I also ran it at load at this speed and at idle/load 464x8.5=3.944GHz 1.208v and made minor adjustments to help my temps track better throughout the range.

Anyway, I think I'm close enough, but if anyone has any suggestions on how I can be more accurate I'm all ears.

[unclewebb]

My original picks for TjMax for RealTemp are partly based on what this chart shows.



http://download.intel.com/technology...ol10_art03.pdf

This graph is from a simulation of a 65nm Core processor but the data was correlated with actual testing and found to be accurate enough.

Depending on what application you're running, the difference between the Tj junction temperature and the diode based case temperature will range from 0C to 5C. There were a lot of applications tested where the difference was zero. I believe that when I was doing my testing with the processor 99% idle that the difference between these two temps would be at the lower end of this range between 0C and 1C.

With 45nm, the gradients have only decreased because everything is closer together. When you run Prime small FFTs on one core, the second core in a Dual Core will heat up to within one degree of the first core even when it is at zero load.

An assumption that Intel might be making is that if your processor is near TjMax then you must be running a high stress app and the difference between your case temperature and your hottest core temperature is probably about 5C. That assumption may not be valid when I am testing with the processor at idle.

I plan to do some more testing when I get the chance.

[CompuTronix]

My Temperature Guide over at Tom's is also based on the same information. Even though my calibration procedure uses SpeedFan to approach the problem from the bottom up, (ambient / Tcase idle / Tjunction load), without using Tjunction Max values, users still find that their resulting core temperatures are consistently within a degree or two on the high side of Real Temp.

I've collected a considerable amount of data over the past year and a half on many variants by observing the relationships between Tcase and Tjunction under a variety of settings and load conditions. I think that a 5c gradient between Tcase and Tjunction is valid at stock clock and Vcore at load. Considering the number of Intel documents that we've both studied, this particular chart, which appears in two separate papers, offers some of the most revealing information.

If we're both wrong, it can't be by much.

[rge]

I think we all agree that best evidence (both papers) suggests the only gradient at idle is across IHS, and IHS gradient is 3C for pentium northwood and likely less on 45/65nm...which means absolute temps are likely 1-2C more than 95 and 2-3C lower than 100 tjmax intel uses.

Would be interesting to see any testing that could shed some light on why the tjmax of 100, is intel rounding up, assuming worst case scenario over time, using loading gradient assumption is an interesting idea, etc. But may be harder to discern couple degrees, much easier disproving 105 where difference was larger.

Wonder if intel thought that releasing the tjmax's would stop the testing, I think only accurate sensors will do that

Edit:
We know there is 5C max gradient at stock settings between cpu diode and DTS diode on 65nm, and was about 6-7C diff on my OC E6850.

I just spent an hour making sure I calibrated both Realtemp die temp and speedfan cpu temp both exactly 2C above IHS at idle, undervolted 1.05 and 6x200mhz...at 85C IHS both Realtemp and Speedfan cpu temp read 87C, at 90 both 92. Since there was half step (?half degree) between two, I set it so core jumped to 92 first then cpu temp, as opposed to vice versa. tjmax was 97, no surprise there. I ran temp up and down about 10 times from 70 to 95C, to make sure I had it right on the money. My DTS seems linear from 70 to 95, either that or on the same curve as IR gun and cpu diode.

Then ran orthos and linpack with my fans off, so DTS temps would get into more accurate range. So now getting 3C higher core temp than cpu diode with linpack on OCed E8400 versus 7C with Oced E6850 (orthos) when I had that calibrated many months ago. (I get 4C difference E8400 with orthos, but that is because die temps are at 58 and reading 1C too high.)

Maybe there is a few degrees less gradient in 45nm vs 65nm as Unclewebb testing core to core suggests, ...unfortunately I cant double check my E6850 since I killed it removing IHS while back.

I think I am going to stick with tjmax 97...makes more sense absolute temp wise, until someone shows me different.

[unclewebb]

If these sensors have some error at TjMax and that error can grow significantly at low temperatures, it makes it pretty much impossible to prove or disprove anything. Page 14 of their recent presentation might explain the motivation for finally releasing some information about TjMax.

Future sensor design enhancement opportunities
–Report temperatures in °C
–DTS range and slope improvements

Core 2 Duo sensors are not always accurate enough for reporting absolute temperatures but looks like Core i7 will be better. Was that bone they threw the enthusiast community an engineering document or a Core i7 sales brochure?

[BeastNotro]

Hey guys i did a fresh Vista 64-bit all updates and SP1 is installed today and i left everything at STOCK in bios, so CPU is at stock and CE1 and speed stepping is on and whatever else in Stock Bios settings.

Why i did a fresh install ... well cause i frigged some files up..... anyhoo i down clocked before i did fresh install.

Using BIOS 1306.

Here is picture of my IDLE temps at STOCK the way all is suppose to be.... not sure if this helps you out all and it is night time here 9:52 PM and it is very cool in my room right now.

How should i calibrate if need to be? as i get confused, i am serious on calibrating stuff.

[Ol'Baditude]

If I were you, I'd get a good room thermometer to make sure you have an accurate idea of your ambient room temperature (not sure what your idea of "cool" is, sry) and adjust the offsets so each core reads roughly 7 degrees above that number. I see you have good air cooling, so that offset amount should do it. They will be constantly changing slightly so you will never get it right on, but it doesn't matter. I left it for 10 minutes to make sure the readings were stable, then rebooted and clocked up.

In my case, since I am under a good water loop, I adjusted my offsets to read 4degC. above ambient at the same underclocked settings you are using. Ambient on that night happened to be 22degC.
My overclocked idle temperatures now read roughly 5 degrees above ambient room temperature now. Delta CPU temp from idle to load ~12Deg.

[BeastNotro]

Here is (Picture Below) of it at OC idle temp and again it is very cool in here this morning 8:25 am .. i checked before and Ambient is usually around 20-24C througout the day, but if she gets really hot out in the day it can be 28C Ambient.

I don't have a thermometer, but i borrowed a Lazor Temp Probe about 3-4 weeks ago and checked on a fairly warm day and it was 24C in my room..

So should i just adjust all cores to 30C? or now thats its at OC 3.6ghz ... adjust them to 37C?

This is IDLE right now (pic Below) ... not calibrated at OC speed.

[Ol'Baditude]

I don't think you want to be doing your offset while you're clocked. I've tried that(saved my underclocked offsets and tested with OC'd calibration) and it made my temps read ~5deg higher on average than they would have doing a normal idle calibration. I think that goes against the whole line of thinking that webb had in mind when he developed the calibration procedure.

If your ambient is 24 deg, and you have your undeclock settings active, I would say that setting all the sensors as close to possible to 30deg would be a perfectly acceptable way to do it.

[WaterFlex]

BeastNotro
Nice temps!!! And it is 2.75! Good job.

[unclewebb]

WaterFlex: The Beast is using RealTemp 2.75 but at the moment he has decided that using TjMax=95C is closer to the truth. The Intel announcement that was going to get everyone on the same page now has some users using, TjMax=95C, some are using TjMax=97C and others are using the Intel recommended TjMax=100C. By not providing us with any test results or any information on the range that TjMax can vary by, we're now guessing more than ever. Intel's official documentation that shows TjMax varies by plus or minus X doesn't help very much.

My opinion at the moment is that TjMax=100C is just that, the absolute maximum TjMax that E8400 processors leave the factory at. The real TjMax might be something like 97.5C +/- 2.5C or somewhere between 95C and 100C. That makes the most sense to me but it's impossible to prove. Intel knows how big the margin of error X is but they're not telling because they don't agree with programs converting digital thermal sensor data to absolute temperatures. These sensors were never designed for that purpose.

I sent the Beast a super sized calibration info package so it should start making a little more sense to him. His Q6600 has nearly identical sensors to the Q6600 I'm using.

[BeastNotro]

READ ALL TEXT

Ok here is some more testing and pictures i am 3.4ghz for now until i figure out something.

Ok as per our conversations in PM's UncleWebb here is some pictures for you to analyze for me.

I did Orthos Blend Test and Prime 95 Small FTT 64-bit (plus a image of no calibration) and you will see Prime 95 Small FTT Pushes a little more.

The tests are Full Load 4 - 10 min or Orthos and or Prime 95.

Calibrated as per you PM ..

TJMax 100 is on Left and TJMAX 95 is on the right after Calibrations Per your PM.. IDLE TEMPS AFTER CALIBRATIONS.




Prime 95 64-bit version SMALL FTT - TJMax 100 is on Left and TJMAX 95 is on the right after Calibrations Per your PM and in the middle is TJMAX 95 NO CALIBRATION.




Orthos Running Blend Test - TJMax 100 is on Left and TJMAX 95 is on the right after Calibrations Per your PM and in the middle is TJMAX 95 NO CALIBRATION.

[JohnZS]

Originally Posted by WaterFlex

JohnZS nice temps dude

Thanks
To be honest I am surprised to

This level of measurement would never be possible were it not for all the hard work put in by Unclewebb.

Not meaning to cause a debate or anything but before I tried RealTemp I was trying to use a competitor application for temperature monitoring...it was that confusing I had no idea what was actually going on in my Quad.

Then along came real temp which had the real TjMAX AND the ability to calibrate (or shall I say account for Extreme Sensors) and now I am confident that my Core2 Quad is running at ~X degrees C

Thank you once again Unclewebb
2.75 caters for Extreme Sensors more than the previous editions.

John

[jason4207]

Beast, are you calibrating idle temps at 3.4GHz?

1st thing to do is pick a Tjmax...that's a tough call.

Next, you need to be super-low...like 200x6=1.2GHz or 266x6=1.6GHz and at ~1.05v to do the idle calibration properly. Once calibrated you can go back to your OC settings and tweak your calibration settings so that your temps track well together when put under load.

[unclewebb]

I was doing some more testing last night with an E8400 and a Q6600 - G0. At TjMax=95C, the IHS measured temp and the RealTemp reported temp are exactly the same at 80C for both of them. If I use the Intel specified TjMax=100C then the core temperature is reported 5C higher than what the IR thermometer shows.

With the processor idle and allowed to heat soak at 80C for 15, 20, 25 minutes, the 5C gradient stays the same. If this is an Intel measured gradient then I'd be interested in seeing their testing. With the known but undocumented amount of error in these sensors, it's impossible to prove what TjMax really is besides likely somewhere between 95C and 100C.

When testing an original B2 E6400, the long assumed TjMax=85C value can't be right if Intel is telling us that TjMax=100C for the E8400. There is a 10C difference between these two so the default would have to be TjMax=90C as rge mentioned before. Same goes for the M0 - E2160 that I re-tested. The Intel documented Thermal Specification for this one doesn't add up.

The next official release of RealTemp will use the higher TjMax values across the board. For the Extremes I'll have to look at the Thermal Specification. If you don't believe a 5C gradient exists then you can deduct 5C from TjMax and go back to RealTemp's original values. You could also split the difference and knock off 2C or 3C from TjMax.

I have to use the Intel released TjMax values and I have to apply that knowledge to 65nm so there will be consistency between 45nm and 65nm. Maybe at the next IDF Intel will get around to releasing some info about 65nm so software developers can do less guessing and assuming when trying to figure out TjMax for 65nm. I'll post some pics in a day or two.

[Freaky Freezer]

I'm very sorry to ask since I know the answer must be hidden somewhere amongst these 87 pages, but can someone tell me what is the "decided" or "standard" Tj. Max for the E8400's or for all the 45nm CPU's?

[rge]

Intel stated that all non-extreme 45nm have tjmax of 100 and that a few C of variance or error will exist part to part.

If you read a lot of intel documents, you will see that intel uses "worst case" or "max over life of cpu" and tests under "worst case" ambient ie 35-40C. Intel does not define tjmax, but if they did I have no doubt they would define as "maximum possible", they do not use averages for critical values. Take a look at tjunctionoffset definition or even power density from intel celeron in pic below.

If your question is what is intel using, ie what is max possible tj, it is 100.

Standard, decided or even average tj....I think as unclewebb just said between 95 and 100. I tried putting in 97.5 for realtemp, but it told me to put in an integer...so I used 97