Vol 1

Thermal Management Specifications
44 Intel® Xeon® Product 2800/4800/8800 v2 Product Family
Datasheet Volume One, February 2014
The temperature reported over PECI is always a negative value and represents a delta
below the onset of thermal control circuit (TCC) activation, as indicated by PROCHOT_N
(see Section 6, “Electrical Specifications”). Systems that implement fan speed control
must be designed to use this data. Systems that do not alter the fan speed need to
guarantee the case temperature meets the thermal profile specifications.
With single thermal profile, it is expected that the Thermal Control Circuit (TCC) would
be activated for very brief periods of time when running the most power intensive
applications. Utilization of a thermal solution that does not meet the thermal profile will
violate the thermal specifications and may result in permanent damage to the
processor. 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 details on system thermal solution design, thermal profiles and
environmental considerations. The upper point of the thermal profile consists of the
Thermal Design Power (TDP) and the associated T
CASE
value.
(x = TDP and y = T
CASE_MAX
@ TDP) represents a thermal solution design point. In
actuality the processor case temperature will not reach this value due to TCC
activation.
Intel recommends that complete thermal solution designs target the Thermal Design
Power (TDP). The Adaptive Thermal Monitor feature is intended to help protect the
processor in the event that an application exceeds the TDP recommendation for a
sustained time period. To ensure maximum flexibility for future requirements, systems
should be designed to the Flexible Motherboard (FMB) guidelines, even if a processor
with lower power dissipation is currently planned. The Adaptive Thermal Monitor
feature must be enabled for the processor to remain within its specifications.
4.1.2 T
CASE
and DTS Based Thermal Specifications
To simplify compliance to thermal specifications at processor run time, the Intel®
Xeon® E7v2 processor has added a Digital Thermal Sensor (DTS) based thermal
specification. Digital Thermal Sensor reports a relative die temperature as an offset
from TCC activation temperature. T
CASE
thermal based specifications are used for heat
sink sizing and DTS based specs are used for acoustic and fan speed optimizations. For
the Intel® Xeon® E7v2 processor family, firmware (for example, BMC or other
platform management devices) will have DTS based specifications for all SKUs
programmed by the customer. SKUs may share T
CASE
thermal profiles but they will
have separate T
DTS
based thermal profiles.
The processor fan speed control is managed by comparing DTS thermal readings via
PECI against the processor-specific fan speed control reference point, or Tcontrol. Both
Tcontrol and DTS thermal readings are accessible via the processor PECI client. At a
one time readout only, the Fan Speed Control firmware will read the following:
• IA32_TEMPERATURE_TARGET MSR
• Tcontrol via PECI - RdPkgConfig()
• TDP via PECI - RdPkgConfig()
• Core Count - RdPCIConfigLocal()
DTS PECI commands will also support DTS temperature data readings.
Also, 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 details on DTS based thermal solution design considerations.