64-bit Intel Xeon Processor with 2MB L2 Cache Thermal/Mechanical Design Guidelines

64-bit Intel® Xeon™ Processor with 2MB L2 Cache Thermal/Mechanical Design Guidelines 17
Thermal/Mechanical Reference Design
Profile, but the diode temperature must remain at or below T
CONTROL
. In other words, there is no
T
CASE
specification for the processor at power levels less than Pcontrol. The thermal solution for
the processor must be able to keep the processor’s T
CASE
at or below the T
CASE
values defined by
the Thermal Profile between the T
CASE
MAX @T
CONTROL
and T
CASE
MAX points at the
corresponding power levels.
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 64-bit Intel
®
Xeon™
Processor with 2MB L2 Cache
The 64-bit Intel Xeon Processor with 2MB L2 Cache 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 64-bit Intel® Xeon™ Processor with 2MB L2 Cache 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 Appendix E for more details on
Figure 2-4. Dual Thermal Profile Diagram