Intel TAT / CoreTemp / IDCC all different temperatures....

[Bail_w]

Look at this.

[RealTelstar]

Look at this.

I tend to believe to coretemp 0.95.

Also, I think newer C2D have 100° tcc (tjunction). I'd like to hear from people with supposedly ~100°C tjunction which week is their c2d.

[unclewebb]

Also, I think newer C2D have 100° tcc (tjunction).

I don't think TjMax=85C applies to any of the Core family of processors, mobile or desktop. I think it came about because a programmer or two misinterpreted bit 30 at location 0xEE and the misinformation spread from there.

My E6400 is one of the early ones which CPUz shows as revision B2 and is based on the original Conroe core.

E6400 - SL9S9
Batch#: L633A988
Pack Date: 12/05/06 ( May 12, 2006 )

[kwalker]

I don't think TjMax=85C applies to any of the Core family of processors, mobile or desktop. I think it came about because a programmer or two misinterpreted bit 30 at location 0xEE and the misinformation spread from there.

My E6400 is one of the early ones which CPUz shows as revision B2 and is based on the original Conroe core.

E6400 - SL9S9
Batch#: L633A988
Pack Date: 12/05/06 ( May 12, 2006 )

You may be right
no one really knows at what point TCC activation occurs for actual core temp calculations read from the DTS.
with the introduction of the Q6600 and a few other newer processors the elimation of the Thermal diode takes away another factor (Tcase)
the temperatures are read directly from the DTS and discrepencys are surfacing in the software readings we thought were reliable.
I will keep following this thread
perhaps some light can be shed on this subject in time.

[Prefixxx]

Just FYI

Send an email to Intel asking about temps and this what I get back.


Hello xxxxx,

Thank you for contacting Intel(R) Technical Support.

Please pay attention to the CPU temperature.
You do not need to pay attention to the core temperature.

If the CPU temperature is lower than 60.1 everything should be OK.

Sincerely,

Axxxx S.
Intel(R) Technical Support

[Elisha]

Just FYI

Send an email to Intel asking about temps and this what I get back.




Please pay attention to the CPU temperature.
You do not need to pay attention to the core temperature.

I agree there....because when i test Orthos and the CPU temp goes above 70.....Orthos fails nomatter what the Core Temp is....Core temp has gone upwards to 79 and has been stable.
but when i open my case side panel.....cpu temps do not exceed 63 degrees. with it closed it get to 70 and above and i have placed a fan everywhere i can think a sensor was located since i thought speedfan was actually reading the NB or PWN temp as CPU temps. but nomatter where i place the fan....the temps do not decrease.

[unclewebb]

I finally got around to doing some more testing today. I'm not quite sure what I've proven besides human stupidity has no bounds but I did end up with lots of interesting data.

I purchased a Fluke IR thermometer recently and a crazy guy at the [H]ard forum jokingly suggested that to get an accurate core temperature reading I should pull off the heatsink and the IHS so I can get a direct shot at the processor. That sounded like an interesting idea so I decided to be the first on my block with a naked Core 2 Duo. I left the IHS on but after it booted up I pulled off the OEM heatsink and fan while it was running. Two strips of masking tape over top of the processor takes away the shine and helps ensure repeatable temperatures from the IR thermometer.



To keep the processor from getting too hot I used an 80mm high speed hand held fan and had no trouble keeping the processor running in the 60C to 70C range.



CoreTemp 0.95 which uses a TjMax=85C for my E6400 was in agreement with the IR readings I was getting at 60C, 70C, 80C and beyond.

To explore when the throttle point kicks in I decided to put the hand held fan down and take pictures as the processor warmed up. Here was the last picture I took before things started to get serious.



When the IR reported my cores getting near 85C, CoreTemp started spitting out these errors every couple of seconds.



I thought for sure a crash was imminent but it kept running as Intel Thermal Monitoring kicked in trying to regain control of this processor by throttling it.



We need a time out to explain the temperature numbers being displayed by these programs.

The DTS is a 7 bit number. What seems to be happening is DTS gets to zero and then when the processor gets 1 degree hotter the value in DTS goes from 000 0000 to 111 1111 binary. That is equivalent to 127. CoreTemp shows with a question mark that there is something wrong here and then reports the value in DTS directly.

CoreTemp -> DTS -> Real_Temp
84 -> 1 -> 84
85 -> 0 -> 85
127 -> 127 -> 86
126 -> 126 -> 87
125 -> 125 -> 88

SpeedFan and TAT work differently. They continue to use the standard formula of Real_Temp = TjMax - DTS so in this case they display:
Temp = 85 - 127 = -42

They report negative numbers starting at -42 and then as the processor continues to heat up the DTS continues to decrease just like usual.

The CoreTemp log file looks interesting.



Core0 maxes out at a DTS value of 116 which, if my calculations above are correct, is actually 97C. Core1 seems to be displayed at a constant 85C reading when temperatures are out of control.

In the following graph, SpeedFan shows after it gets to 85C there is a sharp drop to -42 and then it continues to increase from there. Before my processor caught on fire I decided to put the hand held fan back on it and was able to regain control of this overheating processor.



After taking this processor to hell and back I learned something that I already knew.
The Core 2 Duo is a hell of a processor.

[fgw]

Just FYI

Send an email to Intel asking about temps and this what I get back.


Hello xxxxx,

Thank you for contacting Intel(R) Technical Support.

Please pay attention to the CPU temperature.
You do not need to pay attention to the core temperature.

If the CPU temperature is lower than 60.1 everything should be OK.

Sincerely,

Axxxx S.
Intel(R) Technical Support

the question here is: where is this cpu temperature measured?
looking at the figure of 60.1c i assume this intel guy is talking about tcase as documented in the processor specs. besides tcase is different for different processor families, unfortunately no software is showing this temp anywhere. the recommended method of measuring tcase is by putting a temp probe on the ihs. from looking at intel docs, this is a very tricky task and i doubt many people out here will do this ...
the cpu temperature displayed in bios or read by any other software is simply the temperature measured via the thermal diode and calibrated by some unknown factor. this reading would vary from motherboard manufacturer to motherboard manufacturer and even from one bios rev to the other. don't assume to reading tcase here!