64-bit Intel Xeon Processorwith 1MB L2 Cache Thermal/Mechanical Design Guidelines

Introduction
R
8 64-bit Intel
®
Xeon™ Processor MP with 1 MB L2 Cache
Thermal/Mechanical Design Guidelines
1.4 Definition of Terms
Term Description
Bypass
Bypass is the area between a passive heatsink and any object that can act to form a duct.
For this example, it can be expressed as a dimension away from the outside dimension of
the fins to the nearest surface.
FMB
Flexible Motherboard Guideline: an estimate of the maximum value of a processor
specification over certain time periods. System designers should meet the FMB values to
ensure their systems are compatible with future processor releases.
FSC Fan Speed Control
IHS
Integrated Heat Spreader: a component of the processor package used to enhance the
thermal performance of the package. Component thermal solutions interface with the
processor at the IHS surface.
mPGA604
The surface mount Zero Insertion Force (ZIF) socket designed to accept the 64-bit Intel
®
Xeon™ processor MP with 1 MB L2 cache.
P
MAX
The maximum power dissipated by a semiconductor component.
Ψ
CA
Case-to-ambient thermal characterization parameter (psi). A measure of thermal solution
performance using total package power. Defined as (T
CASE
– T
LA
) / Total Package Power.
Heat source should always be specified for Ψ measurements.
Ψ
CS
Case-to-sink thermal characterization parameter. A measure of thermal interface material
performance using total package power. Defined as (T
CASE
– T
S
) / Total Package Power.
Ψ
SA
Sink-to-ambient thermal characterization parameter. A measure of heatsink thermal
performance using total package power. Defined as (T
S
– T
LA
) / Total Package Power.
T
CASE
The case temperature of the processor, measured at the geometric center of the topside of
the IHS.
T
CASE
_
MAX
The maximum case temperature as specified in a component specification.
TCC
Thermal Control Circuit: Thermal monitor uses the TCC to reduce the die temperature by
using clock modulation when the die temperature is very near its operating limits.
T
CONTROL
A processor unique value, which defines the lower end of the thermal profile and is
targeted to be used in fan speed control mechanisms.
Offset
A value programmed into each processor during manufacturing that can be obtained by
reading IA_32_TEMPERATURE_TARGET MSR. This is a static and a unique value.
TDP
Thermal Design Power: Thermal solution should be designed to dissipate this target power
level. TDP is not the maximum power that the processor/chipset can dissipate.
Thermal Monitor
A feature on the processor that can keep the processor’s die temperature within factory
specifications under nearly all conditions.
Thermal Profile Line that defines case temperature specification of a processor at a given power level.
TIM
Thermal Interface Material: The thermally conductive compound between the heatsink and
the processor case. This material fills the air gaps and voids, and enhances the transfer of
the heat from the processor case to the heatsink.
T
LA
The measured ambient temperature locally surrounding the processor. The ambient
temperature should be measured just upstream of a passive heatsink or at the fan inlet for
an active heatsink.
T
SA
The system ambient air temperature external to a system chassis. This temperature is
usually measured at the chassis air inlets.
U
A unit of measure used to define server rack spacing height. 1U is equal to 1.75 in, 2U
equals 3.50 in, etc.