Processor Thermal Features; Processor Temperature; Adaptive Thermal Monitor - Intel BX80613I7980 Datasheet

Thermal Specifications
6.2

Processor Thermal Features

6.2.1

Processor Temperature

The processor contains 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.
Note: 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.
6.2.2

Adaptive Thermal Monitor

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
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 Guidelines (see
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 processor.
Datasheet, Volume 1
that exceeds the specified maximum
CASE
Section 1.2) for information on
81