P8Z68 Deluxe CPU temps and BIOS version

mjf · 14 Oct 2011

V5.01 of BIOS
First light load after a Real Temp Prime95 test. Note all temps at 26C from Probe II, Real Temp, Core Temp. This is the Core temperature. Note the position on the fan speed curve.

P8Z68 Deluxe CPU temps and BIOS version-light-load-0501-bios-load-test-results.jpg

Next under heavy load from the Prime95 test. Note the temperatures are reasonably consistent. Note the position on the fan speed curve

P8Z68 Deluxe CPU temps and BIOS version-heavy-load-0501-bios.jpg

V7.06 of BIOS
The following screen shots are the same as the above except for the upgraded BIOS. Note the Probe II temperatures are down by approximately 10 Celcius. The fan speed curves are the same but the position on the curve now corresponds to the lower temperature. This lower temperature looks more like Tcase. The preset speed curves like "Standard" make less sense now. They should have been moved to the left.

P8Z68 Deluxe CPU temps and BIOS version-light-load-0706-bios-load-test-results.jpg

P8Z68 Deluxe CPU temps and BIOS version-heavy-load-0706-bios.jpg

Conclusion
I still believe there is a mistake in the fan speed curves which follow Tcase and not Tcore for BIOSs above v5.01. However, for my CPU cooler and case it doesn't end up making much difference to the end maximum core CPU temperature running Prime95. I'll use the User defined curve if it bothers me in the future.

Haru78 · 21 Oct 2011

I have noticed this also today. I just got the P8Z68 Deluxe which ships with 501 bios. I was running it with this bios for a couple days then decided to update and immediately I noticed the 8-10 degree cooler CPU temps. I did a search and came across this forum topic and now I know that I am not the only one to see this issue. Problem is I am not sure what temp to believe now

mjf · 22 Oct 2011

I have sent this issue to ASUS for an answer. I certainly hope I get an answer! If I do I will post it.
The test results strongly suggest:
1) BIOS 0501 report Tcore. BIOS v0603 and above report Tcase.
2) The preset Speed-Temperature curves remain unchanged. They now seem inappropriate for Tcase temperature measurements.

The Speed-Temperature curves are also programmed into the BIOS. A BIOS change is required.

Programs like CoreTemp, RealTemp, SIW, HWMonitor appear to present a measure of Tcore (~8-10 Celsius more than Tcase).
For any safe maximum temperature I recommend you only use your CPU's spec sheet.
For my i7 2600k @3.4GHz my Tcase max is 72.6 Celcius.

Haru78 · 22 Oct 2011

found this on the asus forums

"AiSuite II displays the CPU Surface temperature, also known as Tcase, while CoreTemp or Realtemp shows the raw value read out from PECI, which is the core temperature, also known as Tjunction."

ASUSTeK Computer Inc.-Forum- AL Suite vs Core Temp

still doesnt really explain the nearly 10 degree difference from the two bios versions

mjf · 22 Oct 2011

I've seen that thread and quite frankly it's a bit lame. The final comment suggested to me that it was common knowledge!!! - it is not. I would like an official statement from ASUS not a forum member.
My suggestion to ASUS is:
1) If you make a fundamental change to your measure of CPU temperature then clearly state it in the BIOS update notes. State what temperature you are reporting.
2) Along with this make the appropriate changes to the speed-temperature curves.

In the current "Standard" curve setting 100% fan kicks in with with Tcase=70 Celcius. Given Tcase|max=72.6 Celsius for an i7 2600k how does that make sense

mjf · 28 Oct 2011

UPDATE:
Asus are about to get my No. 1 ranking in unbelievably bad customer support.
They have all the information but it is not being passed on and all I get is the runaround.
So much for a premium Brand.

P8Z68 Deluxe CPU temps and BIOS version

Some Test Results