What is the source of 5.Findings in the Core2 Temp Guide?

Mondoman, it's always a pleasure to see a valued Forum contributor such as yourself, and thanks for asking some excellent questions. The Delta values were acquired from empirical data collected from multiple combinations of motherboards and Core 2 processor variants using stock to high-end coolers.

Yes, you're quite correct; the Delta does vary, as detailed in the Guide:


"Section 6: Scale

Although the Delta between Tcase and Tjunction is constant, these temperatures do not always scale in a precisely linear manner with respect to one another, due to Variables such as Vcore, clock speed, Stepping and Load. Idle at very low Vcore and clock on G0 Stepping may cause Tcase to Tjunction Delta hottest Core to indicate less than 7c, while 100% Workload at very high Vcore and overclock on B2 Stepping at may cause Tcase to Tjunction Delta hottest Core to exceed 18c."


Coolers will affect Deltas, but within the constraints described above. Motherboards will also affect Deltas due to erroneous BIOS versions, which directly affects Tcase (CPU temperature), but have no affect on Tjunction (Core temperatures).

Additionally, since no two processors have identical dynamic operational characteristics such as overclocking ceiling, Vcore tolerance or thermal behavior, there are also mean deviations in Deltas among variants of the same Stepping Revisions. However, the majority of processors will typically fall within their respective +/- 3c tolerance.

If you have any suggestions, I'm always interested in improving the Guide. Thanks again for your questions,

Comp

Comp, I seem to be getting Tcase/Tjunction deltas that are substantially smaller than the 10-15C values. As I test different systems, I will add posts to this thread.

System 1:
Asus F3Jp notebook running 32-bit Vista Home Premium
T7200 CPU (2GHz core) B2 stepping VID: 1.225V
3GB RAM
Tcase measurement software: Notebook Hardware Control 2.0 pre-release 6, CoreTemp 0.96.1
Tjunction measurement software: NHC, CoreTemp as above
Ambient temp: 20C

At idle (0-5% load)
Tcase: 50C
Tj1: 54C
Tj2: 54C

At load (100% load via Orthos)
Tcase: 84C
Tj1: 85C
Tj2: 85C

Hopefully CompuTronix will correct me if I'm wrong.

@red hook - If you haven't calibrated speedfan and/or you're not using the right version of CPU-Z with the correct Tjunction max, your temps might actually be load: 72/75-77.

I finished the whole guide before I started OCing. It really helped.

System 2:
Abit NI8-SLI running 32-bit Win XP Pro
Pentium D 945 CPU (3.4GHz core) C1 stepping 1.23V / Freezer 7 Pro CPU cooler
3GB RAM
Tcase measurement software: Abit uGuru chip/"clock" custom hardware reader
Tjunction measurement software: none, no Tj sensor on Pentium D
ambient temp: 24C

At idle (0-5% load)
"system" sensor: 27C
Tcase: 30C

At load (100% load via Orthos)
"system" sensor: 28C
Tcase: 52C

Comp: as I mentioned above, I read your Guide more than once and found it very informative and helpful. With each reading I get something more, so thank you again.

My question perhaps shows my ignorance, but here it is: why do SpeedFan, CoreTemp and other apps, such as CPU Hardware Monitor, all give me consistent results (without offsets)? I read your offset advice as relating specifically to an anomoly in SpeedFan 4.33. Is this then equally applicable to other apps using the same sensors?

Interestingly, and more confusing to me given your post, I downloaded SpeedFan 4.34 BETA 38 yesterday, and got the same readings as with SpeedFan 4.33!

So perhaps the anomoly is with my particular rig, or of course I may just be going crazy (as some have suggested.)

HaHa Dunkel, I have! Thanks.

UREKA!!!!!!!!!!!!!!????

Just read the latest posts to my vcore and vdroop thread and see what might be the answer, for me. My e4600 has MO stepping and according to Comp this may mean 85 Tjmax, not 100 as previously thought, ans so no offset would be required in SpeedFan, and consistency among all apps is explained!

It's called CPU Hardware Monitor, and you can get it at the same site as CPU-Z (they have a number of apps available.)

I would appreciate your post if you calibrate again as it hopefully will verify our answer.

ooops, I meant Comp's latest post to your SpeedFan questions thread.

Thank you Mondoman.

My appologies to everyone in our O/C and Temp community for not sooner providing this very needed February 7th update to the Temp Guide. The M0 processors have been a major source of controvery, since Intel shuffled the deck several months ago. During this time, "some" M0 processors appeared in the global install-base which did not thermally conform to other variants.

Intel does not provide Tjunction Max specifications for desktops, so I chose to err on the side of safety by using 100c in the Guide, until such time that 85c could be positively verified. Over the past many weeks, I have discussed this issue with Arthur Liberman, the author of Core Temp, who confirmed that "some" M0's were being detected as 100c, while "some" M0's were being detected as 85c, not just by Core Temp, but also by an assortment of other utilities.

It is suspected that "some" M0's are actually recycled E6xx0 variants which have half their L2 cache disabled due to fabrication defects, and are repackaged rather than being scrapped. These supect units, which popped up soon after the release of the M0's, obviously did not have correct factory DTS calibrations, which added to everyone's confusion. It's also likely that "some" E2xx0 units are repackaged E4x00 units. The question of counterfeit processors was also raised.

This factory DTS calibration issue is evidenced by the number of threads which detailed Core temperatures below ambient, as well as Idle and Load temperatures well above other variants, and at the same Vcore and clock. If you recall, we went through a somewhat similar Tjunction Max mess over a year ago when the L2's were released, which increased Tjunction Max from 85c to 100c, and made no sense at the time. And now with the M0's reverting back to 85c, this underscores the need for Intel to provide vital temperature information to it's customers by including Tjunction Max in their specifications.

AMD is no less secretive than Intel, but this Tjunction Max mess reminds me of "Spy Vs Spy". Intel must wake up and realize that we're not constrained to rely strictly upon monitoring Tcase (CPU temp), which is their only published thermal specification for desktops. Since we've all been monitoring Tjunction (Core temps) for quite some time anyway, it's long overdue for Intel to give a little more consideration to their customers. As long as Intel rediculously continues to regard Tjunction Max and Core temperature specifications as corporate secrets, I will feel obligated to continue to maintain the Temp Guide, and to do my best to provide some insight and answers for our readers here on Tom's Forums.

Thanks again Mondoman,

Comp

Dunkel, you're doing a great job with the O/C and Temp learning curves. It's a pleasure to have you here at Tom's.

Mondoman, your temperatures for "System 3" are correct, however, as I'm sure you're aware, "Blend" doesn't provide a steady or continuous 100% workload, although it does yield a more realistic representation of real world maximum loads, which is probably why you chose that particulat test. If we watch the temperatures, or more ideally, if we watch SpeedFan "Charts", then we can observe a graphical representation of the thermal fluctuation which result from load fluctuations during "Blend". Small FFT's will instead give us a very smooth and consistent 100% workload while yielding the highest temperatures, which again, can be observed in SpeedFan "Charts". Heat saturation typically occurs within 7 to 8 minutes, so a test duration of 10 minutes is adequate.