Vol 1

Thermal Management Specifications
58 Intel® Xeon® Product 2800/4800/8800 v2 Product Family
Datasheet Volume One, February 2014
4.2 Processor Core Thermal Features
4.2.1 Processor Temperature
A new feature in the Intel® Xeon® E7v2 processor 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_N 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.
4.2.2 Adaptive Thermal Monitor
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/SVID control) involves the processor adjusting its operating frequency (via
the core ratio multiplier) and input voltage (via the SVID signals). This combination of
reduced frequency and voltage 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.
The Adaptive Thermal Monitor feature must be enabled for the processor to be
operating within specifications. 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 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 Intel® Xeon® Product 2800/4800/8800 v2
Product FamilyIntel® Xeon® Product 2800/4800/8800 v2 Product Family
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.
4.2.2.1 Frequency/SVID Control
The processor uses Frequency/SVID control whereby TCC activation causes the
processor to adjust its operating frequency (via the core ratio multiplier) and VCC input
voltage (via the SVID signals). This combination of reduced frequency and voltage
results in a reduction to the processor power consumption.