IBM Intel Xeon E5506 46M1079 User Manual

104

Intel

®

 Xeon

®

 Processor 5500 Series Datasheet, Volume 1

A new feature in the Intel Xeon processor 5500 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 reaches its maximum operating 

temperature. Adaptive Thermal Monitor uses Thermal Control Circuit (TCC) activation 

to reduce processor power via a combination of methods. The first method 

(Frequency/VID control) involves the processor adjusting its operating frequency (via 

the core ratio multiplier) and input voltage (via the VID signals). This combination of 

reduced frequency and VID results in a reduction to the processor power consumption. 

The second method (clock modulation) 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). 

operating within specifications. The temperature at which Adaptive Thermal 

Monitor activates the Thermal Control Circuit is not user configurable and is not 

software visible. Snooping and interrupt processing are performed in the normal 

manner while the TCC is active.

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

C

 that exceeds the specified maximum temperature 

which 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 

Thermal/Mechanical Design Guide for information on designing a compliant thermal 

solution.

The duty cycle for the TCC, when activated by the Thermal Monitor, is factory 

configured and cannot be modified. 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 

Intel Xeon processor 5500 series.