Jimbo said:
Yeah but both your cores are close to 60c at load, take a look at everst there.
Nah, ya don't say. Have you read the thread? The core temps are nearer junction and higher than Tc which is approximated by the lower reading of 38C, Tc can go to 60C before any problems. 55C for a core temp at 3.6Ghz/1.55v is bloody good for air. There is nothing wrong with considering case temps, its the way its been done for years and recommended by Intel for thermal calculations.
This is a post I stuck up on XS, to discuss Coretemp with its designer.
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Go back to basics.
Arctic Silver Thermal Resistance:
0.0045°C-in²/Watt (0.001 inch layer)
Assumed 1in²/ contact area on IHS.
Tuniq Tower 120 Thermal Resistance:
0.16-0.21 C/W (2000 - 1000 RPM)
Using (
Intel version):
TR = RCS + RSA = (Tc - Ta)/Pd
where:
TR = Total Thermal Resistance
Tc = Tcase, cpu case temperature
Ta = chassis ambient temperature
Pd = total cpu power dissipation
RCS = thermal resistance, case-to-sink
RSA = thermal resistance, sink-to-ambient
TR = 0.16 + 0.0045 = 0.1645 C/W (Tuniq at 2000RPm with AS5)
Ta = 25C (thermometer inside case)
Pd = 65W (stock settings as
Intel TDP ref, 2.4GHz 1.325v, they all say 65W which they can't be, but that's all there is to go on)
0.1645 = (Tc - 25)/65 Therefore Tc = 35.7C
An independent way of estimating the temperature the HSF is actually seeing and proves close to the speedfan/ProbeII values of 34C. If the cpu were at 44C, then at stock speeds and voltages the power dissipation would be Pd = 115W, way more than the stock 65w max thermal design profile.
Going to the other extreme
[email protected]
Using (
online version):
Overclocked Watts = Default Watts * (Overclocked Mhz \ Default Mhz) * (Overclocked Vcore \ Default Vcore)²
Pd = 65*(3600/2400)*(1.5/1.325)² = 125W
Therefore Tc = 45.5C
Again very close to the speedfan/ProbeII 46C!!!
What this says is that the junction core temps may well be higher, but who cares? From the calcs the speedfan/probeII readings are accurate. Of course core temps are relevent to internal Thermtrip# throttling. But it's the Tc case temps that's relevent to system builders. Its these temperatures that are used by Thermal Engineers for system cooling solutions.
Intel (Appendix D) have extensive details on how it should be monitored for testing with thermocouples. And its the only temperature I have any real control over.
The Coolest said:
Intel defines a certain Tjunction/TCaseMax temperature for the processor. In the case of Yonah it is 85C° or 100C°. First of all the program reads from an MSR, detects the Tjunction/TCaseMax temperature. A different MSR contains the temperature data, the data is represented as Delta in C° between current temperature and Tjunction/TCaseMax.
So the actual temperature is calculated like this 'Core Temp = Tjunction/TCaseMax - Delta'
I've got some reliable info about where the register that indicates a CPUs TCaseMax is located, reading that register reveals weather its a 85C TCM chip of a 100C TCM chip. I guess most/all desktops are 85C, the mobiles can vary.
One thing I'm not sure about is the TCaseMax (Tc-max) used by the Coretemp (and TAT by the looks of it) Both designed for mobile CPU's with a higher TCaseMax. Is the position of the DTS very near the core surface/IHS interface, otherwise why reference it against the maximum case temp? Or is it a Tjunction register, then is there a Tj maximum?
If I understand it correctly, say that delta is 20C with Tc-max = 85C
Temp reading = 85-20 = 65C
If say Tc-max is 60C
Temp reading = 60-20 = 40C
I'm curious because as far as I can see the
TCaseMax for the E6600 C2D is 60.1C, not the 85C Coretemp reports. I sure I'm missing something, forgive me if it's a stupid mistake.
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This is how he left it.
The Coolest said:
*EDIT*: I haven't read any updated docs in a while, I might be confused. I will have to recheck and see if the 85C value is indeed the TCaseMax or Tjunction
