Intel i7-950 AT80601002112AA User Manual

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Datasheet 

A new feature in the Intel Core™ i7-900 desktop processor Extreme Edition series and 
Intel Core™ i7-900 desktop processor series is a software readable field in the 
IA32_TEMPERATURE_TARGET register that contains the minimum temperature at 
which the TCC will be activated and PROCHOT# will be asserted. The TCC activation 
temperature is calibrated on a part-by-part basis and normal factory variation may 
result in the actual TCC activation temperature being higher than the value listed in the 
register. TCC activation temperatures may change based on processor stepping, 
frequency or manufacturing efficiencies.

There is no specified correlation between DTS temperatures and processor case 

temperatures; therefore it is not possible to use this feature to ensure the processor 

case temperature meets the Thermal Profile specifications.

The Adaptive Thermal Monitor feature provides an enhanced method for controlling the 

processor temperature when the processor silicon exceeds the Thermal Control Circuit 

(TCC) activation temperature. Adaptive Thermal Monitor uses TCC activation to reduce 

processor power using a combination of methods. The first method (Frequency/VID 

control, similar to Thermal Monitor 2 (TM2) in previous generation processors) involves 

the processor reducing its operating frequency (using the core ratio multiplier) and 

input voltage (using the VID signals). This combination of lower frequency and VID 

results in a reduction of the processor power consumption. The second method (clock 

modulation, known as Thermal Monitor 1 (TM1) in previous generation processors) 

reduces power consumption by modulating (starting and stopping) the internal 

processor core clocks. The processor intelligently selects the appropriate TCC method 

to use on a dynamic basis. BIOS is not required to select a specific method (as with 

previous-generation processors supporting TM1 or TM2). The temperature at which 

Adaptive Thermal Monitor activates the Thermal Control Circuit is factory calibrated and 

is not user configurable. Snooping and interrupt processing are performed in the 

normal manner while the TCC is active.

When the TCC activation temperature is reached, the processor will initiate TM2 in 

attempt to reduce its temperature. If TM2 is unable to reduce the processor 

temperature then TM1 will be also be activated. TM1 and TM2 will work together (clocks 

will be modulated at the lowest frequency ratio) to reduce power dissipation and 

temperature.

With a properly designed and characterized thermal solution, it is anticipated that the 

TCC would only be activated for very short periods of time when running the most 

power intensive applications. The processor performance impact due to these brief 

periods of TCC activation is expected to be so minor that it would be immeasurable. An 

under-designed thermal solution that is not able to prevent excessive activation of the 

TCC in the anticipated ambient environment may cause a noticeable performance loss, 

and in some cases may result in a T

CASE

 that exceeds the specified maximum 

temperature and may affect the long-term reliability of the processor. In addition, a 

thermal solution that is significantly under-designed may not be capable of cooling the 

processor even when the TCC is active continuously. Refer to the appropriate processor 

Thermal and Mechanical Design Guide (see 

) for information on designing a 

compliant thermal solution.

The Thermal Monitor does not require any additional hardware, software drivers, or 

interrupt handling routines. The following sections provide more details on the different 

TCC mechanisms used by the Intel Core™ i7-900 desktop processor Extreme Edition 

series and Intel Core™ i7-900 desktop processor series.