C2D temps... cant figure it out :(

[mrmez]

Ok, sry 4 being a noobz, ive read the Famous C2D Temp Guide by CompuTronix, but i cant get it sussed.

So im rendering some vids atm ~95% load and heres what im getting.

SpeedFan 4.32
CPU: 54c
Core 0: 42c
Core 1: 41c

TAT 2.05
56c
54c

Firstly... tat must be showing the 2 t-junction sensors, and im assuming these are correct?.
So wth is speedfan doing? Shouldnt the 2 cores be around 55c in this case with the one t-case sensor being ~15c cooler?


thx

 

[alpine_sc]

Tjunction Maximum=The maximum temperature that the CPU will run at before throttling down.
For Core 2's, this is either 85C or 100C, depending on how Intel designed it.

Digital Thermal Sensor= The thermal sensor in the CPU that outputs the difference between TjMax and the CPU temperature. For example, if your CPU is at 70C, and the TjMax is 100C, then DTS outputs 30C.

Therefore, to find the temperature of your CPU core, the temperature monitoring software has to subtract TjMax from the DTS value to get your temperature. The problem is how does the software know whether TjMax is 100C or 85C? It has to guess (unless the TjMax is known for that particular model).

What CPU do you have? I know that the e4300 has a TjMax of 100C because I have it.

There is a somewhat certain way to find out if your CPU has a TjMax of 100C or 85C:

1)Download CrystalCPUID (Google it)
-This program can take the DTS value right off the chip
2)Run CrystalCPUID at idle, making sure the CPU is as cold as possible.
3) In the menu at the top, click Function -> MSR Editor
4) In the "MSR Number" input box, type in 0x19C
5) Press RDMSR
6) Find the value under "EAX (31-0)". It should be something like 0x88400000
7) Locate the 2 digits starting from five units to the left. (e.g. the red digits in 0x88400000)
8) This is a hexidecimal number (though it might contain a letter, like "4D"
9) Google up a hexidecimal to decimal calculator, and convert this hexidecimal number to decimal.
10) That's the DTS value!

Now subtract this number from 85C. If it is near, at, or below ambient, then it's wrong, and you know that 100C is the TjMax.

 

[CompuTronix]

mrmez, from the Guide:

Background

... there is much confusion regarding specifications, calibration Offsets and test methods, so results can be difficult to decipher and compare. Therefore, when expressing Idle & Load test Results, it's also necessary to define the Variables as:

Results

Tcase = Idle & Load
Tjunction = Idle & Load, Hottest Core

Variables

Ambient = Intake Temp
Chipset = Model
C2D = Model
CPU Cooler = Model
Frequency = CPU Clock
Load = Test Program
Motherboard = Model
Vcore = CPU Voltage

Also from the Guide:

Testing

PECI = Enabled
Vcore = Manual
C1E / EIST = Disabled
CPU Fan = Manual, 100%
Computer Case Fans = Manual 100%
Computer Case Covers = Installed
Primary Test = TAT @ 100% 10 Minutes
Alternate Test = Orthos @ P9 Small FFT’s 10 Minutes

Results

Tcase[/#0000f f] (Motherboard Utilities) = 30c Idle, 50c Load (SpeedFan: CPU or Temp X)
Tjunction (TAT) Hottest Core = 45c Idle, 65c Load (SpeedFan: Core 0 / Core 1)


Variables

Ambient = 22c
Chipset = 975X
C2D = E6600
CPU Cooler= AC Freezer 7 Pro
Frequency = 3.5 Ghz
Load = TAT @ 100% 10 minutes
Motherboard = Asus P5W DH
Vcore = 1.4

Troubleshooting

(I) If Tcase is higher than Tjunction, then enabling PECI in BIOS may correct inverted temps.

Hope this helps,

Comp