Temperature reporting

[denroc]

Hello, I have two almost identical Thinkcentre computers with similar Intel core 2 duo cpus installed.

PC one (using an the Intel E6400) is reporting cpu temps from high 30c's to low 40c's which seems to be a normal range.

PC two (using an Intel E6700) is reporting from mid teens, 15c, to low to mid 20s shows to be idling temps, with little cpu overhead to be around 19C.

After replacing PC two with an E6300 the average temps are still in the low 20c ..

The only differences I know of between the motherboards is one has a security chip and AMT bios built into the motherboard .

[The Coolest]

It's possible that Core Temp didn't get the TjMax value correctly, as that is the reference it uses to calculate the core temperature.
Go to Options --> Adjust offsets --> Add a 15 offset. This should make it show values that make sense.

[denroc]

If the Tcase rating for the cpu is 60.1c and the Tjmax is set at 85 C then the offset should be approximately 15?

After setting an offset of 15 for both computers ... both PC produced a Tjmax setting of 85c ..

The PC with the E6400 average cpu core readings are in the mid 50s c.

The second PC almost identical PC with the E6700 installed the average cpu core temps are in the mid 30s

The only difference between motherboards that I can determine is the second M55 has an AMT bios and security chip installed.

Perhaps the E6700 is not 100% compatible with the M55 motherboard or there is some sort of damage to the chip or one of the pins?

The cpu passed various tests thrown at it ... I wonder if a chip is overclocked can overclocking potentiall damage or change the dts and/or it's registry ...

From what I can remember the values are stored in registers as a delta value in °C between the current temperature and the Tjunction value given to the cpu.

If for some reason these values are incorrect ... the new set of values would be reflected in the temperature reporting of the cpu?

[The Coolest]

Motherboards don't really affect the temperature.
Temps depend on the cooling solution, thermalpaste state, case airflow, dust, etc.
TcaseMax is not related to TjMax. I suggested 15C offset, because there are two options for TjMax, either 85C or 100C.

[denroc]

Motherboards don't really affect the temperature.
Temps depend on the cooling solution, thermalpaste state, case airflow, dust, etc.
TcaseMax is not related to TjMax. I suggested 15C offset, because there are two options for TjMax, either 85C or 100C.

I was only suggesting if the motherboard was never certified by Lenovo to run an E6700 cpu ... only up to an E6400 ... there sometimes can be incompatibilities issues between the motherboard and cpu ... but as you said this shouldn't effect the cpu temperature reporting ..

There possibly could be damage to the E6700 cpu if it was overclocked at one point ..

or the E6700 cpu is running at ~20c to ~25c lower temperatures then it's predecessors (E6300 and E6400) ...

(Speedfan 4.47 also reports similar temperature differences between the two cpus)

The thermal compound used is Arctic Silver ... was used on both the E6300 and E6700 cpus .. All of the dust was cleaned out of
both computers ... there is plenty of air flow in both PCs.
___
I suppose how I put everything is a bit confusing

There are two M55 Thinkcentres ... both using the same type of Intel Core 2 Duo processors.

and three (3) cpus ... two the cpus (E6300 & E6700) are being tested in one of the PCs .

(M55) PC 1 - has an E6400

(M55) PC 2 - came with an E6300 which was replaced with a E6700

(M55) PC 2 - the cpu was switched back and forth between E6300 and E6700

E6300 reports average temps to be around normal ... without a 15 offset to be around 35 to 40

E6700 reports average temps to be around 20c to 25c lower than while the E6300 is installed in PC 2.

* (At one point I do remember that Tj max was shown as 95c during one test while the E6300 was installed in PC 2 and 85c with the E6700 installed)

[The Coolest]

TjMax depends on the CPU stepping, so different chips may have different TjMax.
If the idle temperature that you get is lower than ambient, then simply apply a 15c offset and the temp should be correct.

[denroc]

TjMax depends on the CPU stepping, so different chips may have different TjMax.
If the idle temperature that you get is lower than ambient, then simply apply a 15c offset and the temp should be correct.

After adding a 15c offset for the E6700 3.66 GHz (core 2 duo) ... the running temperature for both cores is 35c ... with a 35c min. and 45c maximum

The E6300 2.13 GHz (core 2 duo) with 15c offset ... running temperature is around 50c to 55c for both cores ... with a 50c min to 65c maximum

[The Coolest]

You don't have to add an offset to both systems, just the one where you see the low-ball temps.

[denroc]

You don't have to add an offset to both systems, just the one where you see the low-ball temps.

Well ok ... now PC-2 using two different cpus have approx. the same temperatures ..

PC-2 with 15c offset using a E6700 3.66 GHz (core 2 duo) ... the running temperature for both cores is 35c ... with a 35c min. and 45c maximum

PC-2 without offset - using a E6300 1.86 GHz (core 2 duo) with 15c offset ... core1 - ~31c , core2 - ~32c min. - 30 to max. 54c

PC-1 without offset - using a E6400 2.13 GHz (core 2 duo) without 15c offset ... core1 - ~31c , core2 - ~32c min. - 30 to max. 54c

That's good to know. I thought there might be a problem with the Intel E6700 (core 2 duo) seems it is the only cpu of the three that requires an offset.

Testing done with the Intel program ... showed the E6700 to be it to be approx 52c to 62c under maximum ... I did not see any configuration for off-set parameters

From what I can determine both PC-1 and PC-2 are taking readings directly from the CPU's diode ... apparently the temperature reading differences are with the cpu ...

The E6700 was used primarily with a later version TC M series motherboard and bios.