Core Temp is a compact, no fuss, small footprint program to monitor CPU temperature.
Now Vista ready! (x86 and x64)
The uniqueness of it is that it shows the temperature of each individual core in each processor in your system! You can see in real time how the CPU temperature varies when you load your CPU. It's also completely motherboard independent.
Intel and AMD recently published detailed, public information about the "DTS" (Digital Thermal Sensor), which provides much higher accuracy and more relevant temperature reading than the standard thermal diode sensors do.
This feature is supported on all Intel Core and Core 2 based processors as well as the whole AMD's Athlon64 line of CPUs.
Note: AMD Phenom is supported, but it does not report absolute temperature.
Core Temp also has a logging feature, allowing a user to easily record the temperature of his processor(s) over any period of time, then the data can be easily transferred into an excel datasheet for easy graphing.
Core Temp works on Windows 2000, XP, 2003 and Vista (both 32bit and 64bit versions).
This is how the program works:
Intel defines a certain Tjunction temperature for the processor. In the case of Yonah it is 85C or 100C . First of all the program reads from a Model Specific Register (or MSR), and detects the Tjunction temperature. A different MSR contains the temperature data, this data is represented as Delta in C between current temperature and Tjunction.
So the actual temperature is calculated like this 'Core Temp = Tjunction - Delta'
The size of the data field is 7 bits. This means a Delta of 0 - 127C can be reported in theory. But from preliminary tests, the reported temperature doesn't go below 0C , no matter what kind of cooling was used.
AMD chips report the temperature by a special register in the CPU's NB. Core Temp reads that register and uses a formula provided by AMD to calculate the current temperature.
The formula for the K8 is: 'Core Temp = Value - 49'.
The formula for the K10* is: 'CPU Temp** = Value / 8'.
The sensor in AMD CPUs can report temperatures between -49C and 206C.
*K10 = Phenom (Agena), Opteron (Barcelona). The K10 reports a temperature value that is relative to a certain predefined value, it doesn't report the actual processor temperature! So take that into consideration.
**CPU Temp is because the Phenom\Opteron (K10) have only one sensor per package, meaning there is only one reading per processor.
* All Phenom series.
* All Athlon64 series.
* All Athlon64 X2 series.
* All Athlon64 FX series.
* All Turion64 series.
* All Turion64 X2 series.
* All Sempron series. (K8 based)
* Single Core Opterons starting with SH-C0 revision and up. (K8 based)
* All Dual Core Opteron series. (K8 based)
* All Quad Core Opteron series. (K10 based)
* Initial Atom support.
* All Core Solo series.
* All Core Duo series.
* All Core 2 Duo series.
* All Core 2 Quad series.
* All Core 2 Extreme series.
* All Celeron-M 400 and 500 series.
* All Celeron E1000 series.
* All Pentium E2000, E2100 and E2200 series.
* All Dual Core Low Voltage Xeons series (Yonah based. Untested).
* All Xeon 3000, 3200, 3300, 5100, 5300, 5400 series.
The license of this software is Freeware, you can free download and free use this cpu benchmark software.