# Core Temp WRONG!?



## commandercup (May 31, 2008)

Well I've been a firm believer of Core Temp for quite some time now... but after installing my Xigmatek cooler... the temperatures seem to be reporting wrong?

I'm sure its not a problem with the seating since I've spent over 2 hours securing it... and it wont move and when pulled causes the motherboard to pull with it, no its definately on tight

Heres a screenshot of the temperatures.







As you can see, Everest and SpeedFan report relatively similar temperatures ~1-2 C while Core Temp reports the overall CPU temperature as the two cores... whats going on?

I'm running an E2200 which has been lapped...


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## ZenEffect (May 31, 2008)

commandercup said:


> Well I've been a firm believer of Core Temp for quite some time now... but after installing my Xigmatek cooler... the temperatures seem to be reporting wrong?
> 
> I'm sure its not a problem with the seating since I've spent over 2 hours securing it... and it wont move and when pulled causes the motherboard to pull with it, no its definately on tight
> 
> ...



is there a back plate with it?  it could be the tension of the mounting system is causing the motherboard to bow slightly providing inadequate contact.  if that is not the case then i dont know what to tell you other than mabye the base of the hsf may be bowed which on a flat lapped cpu will hurt performance.


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## commandercup (May 31, 2008)

nope, its a push-pin system, but there is no visible warping

also, its definately not bowed because its not a normal heatsink base, it just has exposed aluminum/copper (3 heatpipes are directly exposed on the base) unlike the normal flat copper base

its the HDT-1283... so it should have amazing temperatures, which is why I'm inclined to beleive the lower of the two groups (30's rather than 40's)


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## sneekypeet (May 31, 2008)

other than speed fan and everest read a sensor on the mobo...where IIRC coretemp actuall reads from the core itself, not some sensor on the mobo!

Edit...my E2200 runs hot too!...I figured its because its a glorified Pentium CPU....or as just explained by Jr to me in another thread....these are E4XXX CPU's that didnt make the cut!


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## KBD (May 31, 2008)

I heard that Coretemp reads wrong temps on nvidia chipsets. It does on mine anyway. Everest is also having the same problem on my rig. I found temp probes from my fan controller to be  most reliable.


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## commandercup (May 31, 2008)

well my point is that the temperatures were better with the intel heatsink... after I switched, the temperatures went from ~35 to ~45... 

and I'm 100% sure its not a mounting problem

the E2200 I have is fine, its a great CPU and went to 3.7 on liquid

2.8/9 on stock volts


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## sneekypeet (May 31, 2008)

With my DFI boards Ive always trusted Smart Guardian as being really close....does EVGA have such a utility on the Driver CD?

was this set up on another mobo with the stock cooler...or water?


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## commandercup (May 31, 2008)

nope, I just upgraded the cooler, it was reporting temperatures fine on the stock HSF

and yeah, I did get 3.7 on a DFI motherboard, but thats irrelevant

btw, BIOs reported the temperature at ~35


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## sneekypeet (May 31, 2008)

If all you did was switch the coolers and the Xig is reading higher temps....read previously with coretemp I assume?

I have to say there is something wrong in the application or seating of the new HS!


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## erocker (May 31, 2008)

What method did you use to apply thermal paste to the Xigmatek?

After much testing the method in the pics below give the best results.  First fill in the gaps with thermal paste, then two lines across the aluminum part.


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## Jarman (May 31, 2008)

Alot of the 45nm E series have faulty thermal sensors.  Try Real Temp instead of core temp for them.


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## commandercup (May 31, 2008)

real temp agrees with everest and speed fan... so should I just go with that?

and erocker, I just spread it out on the base... but I'll reapply it like that when I take it off in the future


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## theonetruewill (May 31, 2008)

My chip is in the low 40's for idle. Yeah it's high, but it's a £35 chip that clocks to a £100 one so I don't give a twiddle either way. As long as it doesn't exceed 75*C when under load I'd say to hell with it. I wouldn't normally but these things are throwaways for the price. I know cash is cash but c'mon they are NOT expensive. I also have different tempe for real and coretemp (differ by about 12*C at load, but I have the L2 stepping and I go for coretemp which shows the higher just to be safe.)


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## commandercup (May 31, 2008)

well but my point is that, the temperatures were reported fine before I changed the cooler... so it must be improper mounting?


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## sneekypeet (May 31, 2008)

that was where I was leading earlier...if all other things havent changed...what its the logical issue...the cooler is!


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## theonetruewill (May 31, 2008)

What were the original temps? And are the load temps also very different?


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## sneekypeet (May 31, 2008)

theonetruewill said:


> What were the original temps? And are the load temps also very different?



"well my point is that the temperatures were better with the intel heatsink... after I switched, the temperatures went from ~35 to ~45... "

10*C is even too much for me to say AS5 hasnt set in....most likely used something better anyways!


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## theonetruewill (May 31, 2008)

sneekypeet said:


> "well my point is that the temperatures were better with the intel heatsink... after I switched, the temperatures went from ~35 to ~45... "
> 
> 10*C is even too much for me to say AS5 hasnt set in....most likely used something better anyways!



Apologies I simply did not see that - I rescanned the thread and still didn't so I used Ctrl-F and hey presto.

Try replacing the cooler with the Intel one - check the temps. Then reseat the Xigma one again and check the temps again. I know it's tedious but give it a go.


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## commandercup (May 31, 2008)

eh, I'll try it later... lol, it took me so long to get the xigmatek on...


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## theonetruewill (May 31, 2008)

commandercup said:


> eh, I'll try it later... lol, it took me so long to get the xigmatek on...



I can imagine you're pretty damn bored of putting that cooler on right now.. hard luck mate.


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## echo75 (May 31, 2008)

Actually commandercup, i have been looking at your screenshot carefully and it seems coretemp is the only one reading the temps that are likely correct and both everst and speedfan are likely wrong , i will explain why.

Both speedfan and Everest are reporting that the core temps (temps in the die centers) are the same with CPU temp (surface cpu temps) . The core temps are the temps in the CPU die and ALWAYS quite a few degrees higher than the surface CPU temp . 
Everest claims they are the same and speedfan even reports one core temp cooler than the surface CPU temp.
Also notice that Speedfan is reporting what seems to be 3 cores? core , core 1 and core 2 . you have just 2 cores mate, all points to misreading.

so before u suffer the stress of repeatedly uninstalling your Xigmatek , i actually dont think it has any effect on the way software reads temps. just leave it on if you installed it properly in the first place.

what does your EVGA motherboard temp monitoring software say?


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## commandercup (May 31, 2008)

the board didnt' come with any temperature monitoring software since its the T1 revision, the stripped version which doesn't have nearly as much box content as the A1 did

however... the bios is reading the temperature as 36C... which is close to everest/speed fan

and the extra core readings in those are the cpu temperature itself

but yeah, this is my second time reseating my Xigmatek... but the problem with just leaving it is that it must mean that the Xigmatek for some reason is worse then stock intel cooling!? now that makes no sense at all


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## echo75 (May 31, 2008)

commandercup said:


> and the extra core readings in those are the cpu temperature itself



the cpu temp itself is labeled as "CPU temp"  not Core and u can see that value further up (reported as 34 C in ur screenie).

like i said the core temp and CPU temps CANT almost the same values as what Speedfan reports.


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## dadi_oh (Jun 1, 2008)

erocker said:


> What method did you use to apply thermal paste to the Xigmatek?
> 
> After much testing the method in the pics below give the best results.  First fill in the gaps with thermal paste, then two lines across the aluminum part.



I agree with this assessment. The thermal paste application is critical with these exposed heatpipe designs. I like the example given above. I used a slighty different method on mine. Filled the gaps with compound but instead of applying the compound on the aluminum part I actually spread a very thin layer with a razor blade down the entire length of all 3 heat pipes (basically covering the copper surfaces completely.

I have not tried the other method so I can't say for sure which would work better. However, what I can say is if you just put a blob on the CPU heat spreader and expect it to spread out nicely as it does with a flat heatsink bottom you are going to lose a bunch of compound up the crevices and it will not travel to the extremities of the CPU. That would leave areas of the CPU not contacting the heatsink.

Did you examine how well the thermal paste spread when you removed it the first time? If you do decide to reseat using one of the above methods it would be good if you took a photo of the surface of the CPU right after you remove it so we can see how well it spread.


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## ghost101 (Jun 1, 2008)

Thats such an old version of core temp. M0 chips ahve been corrected since then.


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## commandercup (Jun 1, 2008)

ghost101 said:


> Thats such an old version of core temp. M0 chips ahve been corrected since then.



thank you so much lol!

now the temperatures are fine! they are almost exactly what was listed in everest/realtemp/speedfan

didn't even think to update core temp...


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## Mussels (Jun 1, 2008)

use real temp. coretemp worked accurately on the original core 2 chips (65nm conroe, kentsfield and allendale) but its been inaccurate since then.

Realtemp has adjustments for the latest CPU's.


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## dadi_oh (Jun 1, 2008)

Mussels said:


> use real temp. coretemp worked accurately on the original core 2 chips (65nm conroe, kentsfield and allendale) but its been inaccurate since then.
> 
> Realtemp has adjustments for the latest CPU's.



+1 on Realtemp. Coretemp was giving wrong readings on my E8200 and E8400 since Coretemp used the wrong Tj max assumption. The writer of Realtemp corrected the wrong assumption by actually measuring it.


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## Mussels (Jun 1, 2008)

intel states numbers for the max temp, which is supposed to read like  

Tjunction -40C (max temp) the problem is, without knowing what TJ is... you're screwed. the Realtemp maker simply went and tested naked core2 chips with an infrared thermo, to see the real TJ temps.


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## unclewebb (Jun 1, 2008)

Here's the testing I did on my revision M0 E2160.  

http://www.xtremesystems.org/forums/showpost.php?p=2844886&postcount=423

After seeing this I concluded that TjMax is 85C and not 100C like CoreTemp used to assume.


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## Mussels (Jun 1, 2008)

unclewebb said:


> Here's the testing I did on my revision M0 E2160.
> 
> http://www.xtremesystems.org/forums/showpost.php?p=2844886&postcount=423
> 
> After seeing this I concluded that TjMax is 85C and not 100C like CoreTemp used to assume.



thanks for that.


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## theonetruewill (Jun 1, 2008)

unclewebb said:


> Here's the testing I did on my revision M0 E2160.
> 
> http://www.xtremesystems.org/forums/showpost.php?p=2844886&postcount=423
> 
> After seeing this I concluded that TjMax is 85C and not 100C like CoreTemp used to assume.


OK you've finally convinced me to start using realtemp as my monitoring program. Your post as well as the neat addition "to-tray" feature (yeah I know we've been pissing you off there) clinched it.

People should probably have a read of this too if they're still decinding which is the correct one to use;


CompuTronix said:


> *Unclewebb*, I am the author of the *Core 2 Quad and Duo Temperature Guide* over at Tom's: http://www.tomshardware.com/forum/221745-29-core-quad-temperature-guide#
> 
> I first became interested in this topic of "apples and oranges thermal fruit salad" in November 06. I wrote the Temp Guide in early February 07 because users were very confused, and no one else was committed to taking on the task of cleaning up this incredible mess that Intel has so inconsiderately dumped on us, their customers. Since the topic sorely needed attention, my Temp Guide was immediately Sticky'd, and has been a work in progress ever since.
> 
> ...


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## unclewebb (Jun 1, 2008)

*E8400 Test*

Thanks for the positive feedback.  

On some forums, some people think I've just pulled these numbers out of a hat or something but I did a lot of testing before writing RealTemp and I've done a lot of testing since.  I haven't seen *any* real world testing from the competition.  

When you see the testing I've done, like this one with my E8400, there isn't a lot left to argue about:

http://www.xtremesystems.org/forums/showpost.php?p=2883315&postcount=573


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## Mussels (Jun 1, 2008)

unclewebb said:


> Thanks for the positive feedback.
> 
> On some forums, some people think I've just pulled these numbers out of a hat or something but I did a lot of testing before writing RealTemp and I've done a lot of testing since.  I haven't seen *any* real world testing from the competition.
> 
> ...



after reading the original thread about realtemp, i dont see what was left to argue - running a chip naked and seeing what temps it throttles at, is kinda... obvious? You did something that took a fair bit of effort and a mild amout of risk, and got a program with the most accurate temp readings so far. Its a far cry from the days of temp sensors in the CPU sockets...


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## unclewebb (Jun 1, 2008)

Thanks.  It turns out the risk is highly overestimated.  My E8400 must have thought it was on a holiday when I introduced it to the test bed at 1600 MHz, 1.08 volts and less than 40C.

Soon after, the holiday was over and it was time to put it to work. 







With all the early reports of degrading 45nm chips I was a little worried but it seems to have survived.  It needs more voltage than the good 45nm chips but no complaints with how it runs.


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## rampage (Jun 1, 2008)

Nice OC unclewebb

Also for no real reason i thought i would let you know that i have the same idle temp issue my E6750, i am underclocking my chip for a HTPC and am running it at 250 * 8 = 2000mhz @1.1v but your software is buy far the best at reading the chip at load or during normal use


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## theonetruewill (Jun 1, 2008)

On a separate note - 

ULTIMATE THREAD HIIJACK!


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## unclewebb (Jun 1, 2008)

rampage: Read the RealTemp docs and try doing the calibration with your case open and compare your idle temps to your room temperature.  If you have been idle for 5 or 10 minutes then there is usually about a 4C difference.

You should be able to find some Calibration factors for RealTemp that will get your idle temps much closer to reality.  Even if they are not perfect, they will be much closer and will also improve the accuracy of your load temps up to about 60C.  When I originally checked my E6400, it needed a +2 calibration.  That sounds like a good starting point for you and then adjust it so both cores idle at the same temperature.

http://www.techpowerup.com/realtemp/docs.php


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## sneekypeet (Jun 1, 2008)

What I am really curious about is how we go from temps on a E2200 to temps on a E8xxx, they have nothing to do with each other.

So we are just supposed to ignore that at load this thing reads in the 70*C sometimes?


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## unclewebb (Jun 2, 2008)

I apologize for getting off topic.  As the programmer of RealTemp, I thought people might be interested in the testing that is behind the program.  There's not a lot of difference between the sensors on these chips.  Very few are even close to accurate at idle and most are extremely accurate at full load.

If RealTemp says you are at 70C at full load then you are at 70C unless your sensors are damaged but few are.  If a chip is running that hot, it's maximum overclock will be heat limited.  It could be an issue with the IHS to core contact.  That happens sometimes.  My revision M0 E2160 was one of the coolest running processors I've had.

For far too long people have been taking whatever CoreTemp says as accurate and I just wanted to set the record straight.

I also wanted to show that you can test a processor this way without too much risk of damaging it as long as you use some common sense.  I wish more users would step forward and do their own testing like this so more people can see that *CoreTemp is WRONG* sometimes which I thought was the topic.

I'll head back to XS and keep quiet here.


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## theonetruewill (Jun 2, 2008)

Personally I am beginning to believe that my chip easily hitting above 70*C is just a bit odd since it's only on 1.45v and the cooler isn't that bad. The case has reasonable airflow and I think a temperature in the low 60's as real temp states is a bit more believable for my L2 revision E2140- even with the fairly large frequency increase.


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## unclewebb (Jun 2, 2008)

The L2 E4300 is where CoreTemp first went wrong.  He originally used TjMax=85C which is correct for that processor but users convinced him that the below ambient core temperatures that were being reported were wrong so they convinced him that TjMax was wrong.  The only choices back then based on the documentation for mobile core processors was 85C or 100C.  They said 85C was wrong so he chose 100C and L2 processors and many others have been reported wrong by CoreTemp and other programs ever since.

My M0 runs very cool and the L2 CPUs aren't much different.  By testing a variety of processors, 45nm, 65nm, dual and quad core, early and late revisions you see a very clear pattern develop with these chips and its really not that complicated.  The hard part is convincing users that the temps they've been seeing for the last year are wrong, and sometimes very wrong.  As far as I know the latest version of CoreTemp 0.99 is still using TjMax=105C for the E8400.  This combined with ignoring the trouble these sensors have at idle and my reported temps are off by 18C.

E2200 processors that are using TjMax=100C might have idle temperatures that are out by over 20C.


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