Intel AT80604004881AA User Manual
Thermal Specifications
120
Intel® Xeon® Processor 7500 Datasheet, Volume 1
6.2
Processor Thermal Features
6.2.1
Thermal Monitor Features
The Intel® Xeon® processor 7500 series provides two thermal monitor features,
Intel® Thermal Monitor (“TM1”) and Intel® Thermal Monitor (“TM2”). Both Intel®
Thermal Monitor 1 and 2 must be enabled in BIOS for the processor to be operating
within specifications. When both are enabled, Intel® Thermal Monitor 2 will be
activated first and Intel® Thermal Monitor 1 will be added if the use of Intel® Thermal
Monitor 2 alone does not meet the temperature target.
Intel® Thermal Monitor (“TM1”) and Intel® Thermal Monitor (“TM2”). Both Intel®
Thermal Monitor 1 and 2 must be enabled in BIOS for the processor to be operating
within specifications. When both are enabled, Intel® Thermal Monitor 2 will be
activated first and Intel® Thermal Monitor 1 will be added if the use of Intel® Thermal
Monitor 2 alone does not meet the temperature target.
6.2.2
Intel® Thermal Monitor 1
The Intel® Thermal Monitor 1 feature helps control the processor temperature by
activating the Thermal Control Circuit (TCC) when the processor silicon reaches its
maximum operating temperature. The TCC reduces processor power consumption as
needed by modulating (starting and stopping) the internal processor core clocks.
Intel® Thermal Monitor 1 or Intel® Thermal Monitor 2 must be enabled for the
processor to be operating within specifications. The temperature at which Intel®
Thermal Monitor 1 activates the thermal control circuit is not user-configurable and is
not software-visible. Bus traffic is snooped in the normal manner, and interrupt
requests are latched (and serviced during the time that the clocks are on) while the
TCC is active.
activating the Thermal Control Circuit (TCC) when the processor silicon reaches its
maximum operating temperature. The TCC reduces processor power consumption as
needed by modulating (starting and stopping) the internal processor core clocks.
Intel® Thermal Monitor 1 or Intel® Thermal Monitor 2 must be enabled for the
processor to be operating within specifications. The temperature at which Intel®
Thermal Monitor 1 activates the thermal control circuit is not user-configurable and is
not software-visible. Bus traffic is snooped in the normal manner, and interrupt
requests are latched (and serviced during the time that the clocks are on) while the
TCC is active.
When Intel® Thermal Monitor 1 is enabled, and a high temperature situation exists
(that is, TCC is active), the clocks will be modulated by alternately turning the clocks
off and on at a duty cycle specific to the processor (typically 30 - 50%). Cycle times are
processor speed dependent and will decrease as processor core frequencies increase. A
small amount of hysteresis has been included to prevent rapid active/inactive
transitions of the TCC when the processor temperature is near its maximum operating
temperature. Once the temperature has dropped below the maximum operating
temperature, and the hysteresis timer has expired, the TCC goes inactive and clock
modulation ceases.
(that is, TCC is active), the clocks will be modulated by alternately turning the clocks
off and on at a duty cycle specific to the processor (typically 30 - 50%). Cycle times are
processor speed dependent and will decrease as processor core frequencies increase. A
small amount of hysteresis has been included to prevent rapid active/inactive
transitions of the TCC when the processor temperature is near its maximum operating
temperature. Once the temperature has dropped below the maximum operating
temperature, and the hysteresis timer has expired, the TCC goes inactive and clock
modulation ceases.
With a thermal solution designed to meet the Intel® Xeon® processor 7500 series
Thermal Profiles, 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. 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.
Thermal Profiles, 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. 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.
The duty cycle for the TCC, when activated by the Intel® Thermal Monitor 1, is factory-
configured and cannot be modified. Intel® Thermal Monitor 1 does not require any
additional hardware, software drivers, or interrupt handling routines.
configured and cannot be modified. Intel® Thermal Monitor 1 does not require any
additional hardware, software drivers, or interrupt handling routines.
6.2.3
Intel® Thermal Monitor 2
The Intel® Xeon® processor 7500 series adds supports for an enhanced thermal
monitor capability known as Intel® Thermal Monitor 2. This mechanism provides an
efficient means for limiting the processor temperature by reducing the power
consumption within the processor. Intel® Thermal Monitor 1 or Intel® Thermal Monitor
2 must be enabled for the processor to be operating within specifications. Intel®
Thermal Monitor 2 requires support for dynamic VID transitions in the platform.
monitor capability known as Intel® Thermal Monitor 2. This mechanism provides an
efficient means for limiting the processor temperature by reducing the power
consumption within the processor. Intel® Thermal Monitor 1 or Intel® Thermal Monitor
2 must be enabled for the processor to be operating within specifications. Intel®
Thermal Monitor 2 requires support for dynamic VID transitions in the platform.