Intel Xeon Processor 2.80 GHz Thermal/Mechanical Design Guidelines

Thermal/Mechanical Reference Design
18 Dual-Core Intel
®
Xeon
®
Processor 2.80 GHz Thermal/Mechanical Design Guidelines
Refer to Section 2.3.1 for the implementation of the T
CONTROL
value in support of fan speed
control (FSC) design to achieve better acoustic performance.
2.2.3 Dual Thermal Profile Concept for the
Dual-Core Intel Xeon Processor 2.80 GHz
The Dual-Core Intel Xeon processor 2.80 GHz is designed to go into various form factors,
including the volumetrically constrained 1U and custom blade form factors. Due to certain
limitations of such form factors (i.e. airflow, thermal solution height), it is very challenging to meet
the thermal requirements of the processor. To mitigate these form factor constraints, Intel has
developed a dual Thermal Profile specification, shown in Figure 2-4.
The Thermal Profile A is based on Intel’s 2U+ air cooling solution. Designing to Thermal Profile A
ensures that no measurable performance loss due to Thermal Control Circuit (TCC) activation is
observed in the processor. It is expected that TCC would only be activated for very brief periods of
time when running a worst-case real world application in a worst-case thermal condition. These
brief instances of TCC activation are not expected to impact the performance of the processor. A
worst case real world application is defined as a commercially available, useful application which
dissipates a power equal to, or above, the TDP for a thermally relevant timeframe. One example of
a worst-case thermal condition is when a processor local ambient temperature is at or above 43 °C
for Dual-Core Intel Xeon processor 2.80 GHz Thermal Profile A.
Thermal Profile B supports volumetrically constrained platforms (i.e. 1U, blades, etc.), and is
based on Intel’s 1U air cooling solution. Because of the reduced capability represented by such
thermal solutions, designing to Thermal Profile B results in an increased probability of TCC
activation and an associated measurable performance loss. Refer to Dual-Core Intel® Xeon®
Processor 2.80 GHz Datasheet for more details on the Thermal Monitor features. Measurable
performance loss is defined to be any degradation in the processor’s performance greater than
1.5%. The 1.5% number is chosen as the baseline since the run-to-run variation in a given
performance benchmark is typically between 1 - 2%.
Figure 2-4. Dual Thermal Profile Diagram
Pcontrol_base_A
TDP
T
CASE
T
CASE
MAX B
T
CASE
@
Pcontrol_base
Thermal Profile B
T
CASE
MAX A
Thermal Profile A
Pcontrol_base_B
Pcontrol_base_A
TDP
T
CASE
T
CASE
MAX B
T
CASE
@
Pcontrol_base
Thermal Profile B
T
CASE
MAX A
Thermal Profile A
Pcontrol_base_B