Processor Case Temperature Measurement Location - Intel X5365 - Xeon 3.0 GHz 8M L2 Cache 1333MHz FSB LGA771 Quad-Core Processor Design Manual

Thermal/Mechanical Reference Design
Figure 2-4.

Processor Case Temperature Measurement Location

To ease the burden on thermal solutions, the Thermal Monitor feature and associated
logic have been integrated into the silicon of the processor. One feature of the Thermal
Monitor is the Thermal Control Circuit (TCC). When active, the TCC lowers the
processor temperature by reducing power consumption. This is accomplished through a
combination of Thermal Monitor and Advanced Thermal Monitor (TM2). Thermal
Monitor modulates the duty cycle of the internal processor clocks, resulting in a lower
effective frequency. When active, the TCC turns the processor clocks off and then back
on with a predetermined duty cycle. Thermal Monitor 2 activation adjusts both the
processor operating frequency (via the bus multiplier) and input voltage (via the VID
signals). Please refer to the Quad-Core Intel® Xeon® Processor 5300 Series Datasheet
for further details on TM and TM2.
PROCHOT# is designed to assert at or a few degrees higher than maximum T
(as specified by the thermal profile) when dissipating TDP power, and can not be
interpreted as an indication of processor case temperature. This temperature delta
accounts for processor package, lifetime, and manufacturing variations and attempts to
ensure the Thermal Control Circuit is not activated below maximum T
dissipating TDP power. There is no defined or fixed correlation between the PROCHOT#
assertion temperature and the case temperature. However, with the introduction of the
Digital Thermal Sensor (DTS) on the Quad-Core Intel® Xeon® Processor 5300 Series,
the DTS reports a relative temperature delta below the PROCHOT# assertion
temperature (see
Thermal solutions must be designed to the processor specifications (i.e Thermal Profile)
and can not be adjusted based on experimental measurements of T
or Digital Thermal Sensor on random processor samples.
By taking advantage of the Thermal Monitor features, system designers may reduce
thermal solution cost by designing to the Thermal Design Power (TDP) instead of
maximum power. TDP should be used for processor thermal solution design targets.
TDP is not the maximum power that the processor can dissipate. TDP is based on
measurements of processor power consumption while running various high power
applications. This data set is used to determine those applications that are interesting
Quad-Core Intel® Xeon® Processor 5300 Series Thermal/Mechanical Design Guidelines (TMDG)
Section 2.2.2 for more details on the Digital Thermal Sensor).
CASE
when
CASE
, PROCHOT#,
CASE
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