Which to believe?

[alexbruce]

Hey,

I have a Q6600 w/ OCZ Vendetta 2 on a DFI X48-T2RS, this is a question that's been answered for several different types of cooling software probs BUT..

who should i take an accurate reading from?

Core-Temp says one temperature and my bios/DFI Smart Guardian say another... the difference isn't huge, about 6 degrees at the time of writing, Smart guardian only gives the CPU temp as 1 number, so i'm guessing it does the highest core?..

Can anyone who used both or knows something i don't chip in and help me out?

Thanks!

 

[Liderc]

Believe core-temp is the most accurate for Q6XXX chips.

 

[Shadow703793]

Use RealTemp.

 

[CompuTronix]

... Core-Temp says one temperature and my bios/DFI Smart Guardian say another... the difference isn't huge, about 6 degrees at the time of writing, Smart guardian only gives the CPU temp as 1 number, so i'm guessing it does the highest core?...

alexbruce,

6c is in the ballpark, but it's not exactly accurate.

BIOS is CPU temperature, which is Tcase (Intel's terminology), and Core temperature is Tjunction (Intel's terminology). When calibrated, there is a 5c difference between CPU temperature and Core temperature, however, CPU temperature reads from a single Analog Thermal Diode integrated into the CPU package substrate layers, while Core temperature is read from the DTS (Digital Thermal Sensors) on each Core.

CPU temperature and Core temperatures function completely independently from one another, so the temperature you see in BIOS and Smart Guardian is CPU temperature, and is definately not the hottest Core.

All of this is thoroughly explained in my Core 2 Quad and Duo Temperature Guide - http://www.tomshardware.com/forum/221745-29-core-quad-temperature-guide

The Guide explains how temperatures work, and how to uniformly test, accurately calibrate, and properly monitor your temperatures. From the Guide:

Section 1: Introduction

Core 2 Quad and Duo processors have 2 different types of temperature sensors; a CPU case (not computer case) Thermal Diode centered under the Cores, and Digital Thermal Sensors located on each Core. The case Thermal Diode measures Tcase (Temperature case), which is CPU temperature, and the Digital Thermal Sensors measure Tjunction (Temperature junction), which is Core temperature. Since these sensors measure 2 distinct thermal levels, there is a 5c temperature difference between them, which is Tcase to Tjunction Gradient. C2Q's have 1 Tcase and 4 Tjunction sensors, while C2D's have 1 Tcase and 2 Tjunction sensors. Uncalibrated default temperatures are seldom accurate.

Comp

 

[CompuTronix]

Liderc and zipzoomflyhigh,

Real Temp allows you to calibrate Tjunction Max for each individual core, while Core Temp only allows a single Tjunction Max offset for all cores. Additionally, Real Temp is the only temperature monitoring utility which also allows separate idle calibrations for each individual core. Real Temp has several other unique features such as the "Sensor Test" which allows you to identify sensors that are not responding correctly to changes in temperature from full load to dead idle.

Comp

 

[randomizer]

Without calibration, accuracy is arbitrary.

 

[bf2gameplaya]

I'll expand on randomizers comment: They are probably both accurate relative to each other and probably both accurate to the thermometer in your room but none of them are correct.

What's important for you to do is the process of calibration, where you zero the scales and then find the offset. It's easy in concept but tricky in practice...find the temps of ALL your thermometers the split second you turn your PC on. This includes the one in your room.

Then you can take samples of the temperature over time, and see how all the different results compare to each other, you can see if the relationship is linear, which it should be. Most diodes have 255 temperature reporting states which can be roughly stated as half-degree Fahrenheit sensitivity under the best conditions..my best understanding is +/- 3 degrees F is typical resolution.

 

[hairycat101]

Put your finger on it to see if it is hot.

 

[jeanluclariviere]

^ +1 I did that once lol it hurt.