Ok so what is the TJMAX of the Q6600? I want to calibrate my cpu temp programs. I have found that intel released a thing saying it was 90c. But nobody is really sure whats right/ I know real temp uses 100c as the TJMAX and PCWizard2008 uses 95C I wanna what the correct one is so I can get the most accurate reading from my programs. Does anyone know how to adjust the TJMAX in the nvidia system tools? I had my TJMAX to 90 and real temp reported a core idling at 21c in a 21c room. I think thats a little too low even tho I have a lapped TRUE with 2 100cfm fans strapped to it and 8 100cfm case fans in my case. Anyone do any testing on what intel released? or any testing at all and found something different? Any input would be appreciated... Thanks Also one last thing which is more accurate of a reading for temp programs the CPU temp reading it gives or the individual core temps it gives? Thanks


Intel Master

All that text, and you never mentioned whether you have a G0 Stepping or a B3 Stepping. This is all about specifications, so please be specific, because it makes a difference. Assuming you have a G0 Stepping, I'll put this into perspective for you.

Core 2 Quad's have a single CPU temperature sensor (Tcase), and four Core temperature sensors (Tjunction). For the Q6600 G0, Intel's Thermal Specification is 71c, which is shown in their Processor Spec Finder - http://processorfinder.intel.com/details.aspx?sSpec=SLACR

71c is maximum CPU temperature (Tcase Max), NOT Core temperature, which is a common misconception among many users. Also, there's a 5c Gradient between CPU temperature (lower) and Core temperature (higher), which is shown in the following Intel document - http://arxiv.org/ftp/arxiv/papers/0709/0709.1861.pdf

Although maximum Core temperature (Tjunction Max) is 100c, which is for Throttle and Shutdown protection, the corresponding CPU temperature would be 95c; far too hot for sane operation. As such, CPU temperatures above 71c and Core temperatures above 76c should be considered as an "overtemp" condition.

SpeedFan shows CPU temperature AND Core temperature, while Real Temp shows Core temperatures ONLY. Both programs allow calibrations. Intel has stated that the Digital Thermal Sensors (DTS) used for monitoring Core temperatures are accurate at very high temperatures, become less accurate as temperatures decrease, and may be unreliable at idle temperatures.

On the other hand, the Analog Thermal Diode used for monitoring CPU temperature is linear from idle thru high temperatures, which is why, as per agreement with Intel, motherboard manufacturers do not include Core temperature in their monitoring utilities found on the installation disk, such as Asus Probe.

Never assume that default temperatures are accurate. The accuracy of CPU temperature is determined by BIOS calibrations, but can be closely calibrated in SpeedFan. The accuracy of Core temperatures are determined by Intel factory calibrations, but can be closely calibrated in SpeedFan and Real Temp.

Prime95 Blend, or OCCT (Linpack), or CPU Burn Test (LinX) are cyclic workloads, which produce fluctuating temperatures. While these are useful for stability testing, they're inappropriate for thermal testing. Prime95 Small FFT's is the standard for thermal testing, because it's a steady-state 100% workload. Since thermal saturation is reached within 7 to 8 minutes, a 10 minute test is adequate. Keep in mind that even the most processor intensive games or applications will rarely exceed 70% to 85% sustained workload.

From the Core i7 and Core 2 Temperature Guide: http://www.tomshardware.com/forum/221745-29-sticky-core-core-temperature-guide

Scale 3: Quad
Q9x50: Tcase Max 71c, Stepping E0, TDP 95W, Idle 16W
Q9x50: Tcase Max 71c, Stepping C1, TDP 95W, Idle 16W
Q9400: Tcase Max 71c, Stepping R0, TDP 95W, Idle 16W
Q9300: Tcase Max 71c, Stepping M1, TDP 95W, Idle 16W
Q8x00: Tcase Max 71c, Stepping R0, TDP 95W, Idle 16W
Q8200: Tcase Max 71c, Stepping M1, TDP 95W, Idle 16W
Q6x00: Tcase Max 71c, Stepping G0, TDP 95W, Idle 16W<--Q6600 G0

--70--/--75--75--75--75-- Hot
--65--/--70--70--70--70-- Warm
--60--/--65--65--65--65--Safe <--
--25--/--30--30--30--30-- Cool

CPU temperature = Tcase
Core temperature = Tjunction

Does this answer your questions?

Comp :sol:


yea sorry about not teling you I had GO stepping which I do but I totally forgot. So what do you think I should set the TJMax to in core temp and pcwizrd2008? 90c or 95 or 100?


Intel Master

I believe that I've already answered this question:

October of last year, following the Intel Developers Forum (IDF 2008) held in Taipei, Taiwan, Intel finally made it clear that the Tjunction Max value for your Q6600 G0 is 100c, which is the default value shown in Real Temp. If you'd like further confirmation, then ask the author of Real Temp, Kevin Glynn (unclewebb) by logging onto XtremeSystems - http://www.xtremesystems.org/forums/showthread.php?t=179044

The Real Temp thread at XtremeSystems is the single most informative source available anywhere on the Internet concerning Intel Core temperatures. Since the early stages of developement, and throughout the past 14 months, I have followed all 141 pages of the Real Temp thread, and have been in correspondence with Kevin, in order to share our research and test findings. You'll find that he's very responsive, so if you post a question on his thread, he'll answer you in short order.

In addition to being the ONLY core temperature monitoring utility which offers Tjunction Max calibrations AND Tjunction Idle calibrations, Real Temp is the only freeware utility available which is based upon real-world testing, as well as analysis of Intel's engineering documentation. Real Temp's Tjunction Max tables are accurate for each processor variant, which is precisely why I endorse Real Temp in my Core i7 and Core 2 Temperature Guide, and recommend it over Core Temp.

Keep in mind that Tjunction Max is not an exact figure, but is also referred to by Intel as "Tj Target" which may vary from part to part, and core to core, and is evidenced by differences in individual core temperatures that are commonly seen on the same processor. More exactly, Tjunction Max is the "average" or "mean" Core temperature of all Cores, with the exception of disregarding an individual Core which is obviously far out of calibration tolerance.

Tjunction Max values are affected by Digital Thermal Sensor (DTS) variables such as factory calibrations, slope error and linearity. This is why Tjunction Max (maximum Core temperature) is a round figure, such as 100c for the Q6600 G0, or 90c for the obsolete Q6600 B3, while Tcase Max (maximum CPU temperature) is an exact figure to the tenth of a degree, such as 71.4c for the Q9650 - http://processorfinder.intel.com/details.aspx?sSpec=SLB8W

Further, since the calibration method I developed for my Guide does not require or use Tjunction Max values to achieve CPU temperature and Core temperature accuracy, the calibration results show that the actual Tjunction Max for the Q6600 G0, as well as the Q9650 averages between 97c and 98c. Conversely, all the Core i7 processors that I've tested are spot-on at Tjunction Max 100c. I have tested and calibrated many Q6600 G0's, Q9650's and i7 920's, and the results have been verified as consistent and repeatable.

Since you're interested in achieving the most accurate temperatures for your rig, my best advice to you is either go with 100c, or plug in a closer value of 98c, or perform the SpeedFan calibrations detailed in my Guide to find the exact Tjunction Max value of your particular Q6600 G0.

Comp :sol:


I just read an article and a forum that Unclewebb said that the TJMAX of the Q6600 GO is 95c because he tested it by undervolting and underclocking the cpu and removing the HS and using a IR gun to find when it shut down and it was at 93c


Intel Master
If you investigate further, you'll find that his IR testing was conducted earlier last year, which at 95c, was off by 2c to 3c due to a few low order Gradients insulated from the IR device. I believe that Real Temp 2.5 was the last version with 95c, but all subsequent versions are 100c, which also conforms with Intel's stated 100c. The current release version is 3.0, and the latest BETA version is 3.2.

Behind the scenes, his research agrees closely with mine, which reveals that 97c to 98c is as close as we can get. Again, if you want to calibrate your temperatures specifically to your particular Q6600 as accurately as possible, then just perform the calibrations in my Guide. It's not Calculus, it's simple 4th grade math, so anyone should be able to do it.