Intel X5365 Design Guide - Page 27

Thermal/Mechanical Reference Design Figure 2-10. Dual Thermal Profile Diagram TCASEMAX B TCASEMAX A TCASEMAX@ P_PROFILE_MIN Thermal Profile B Thermal Profile A TCASE P P _PROFILE_MIN_B _PROFILE_MIN_A Power TDP 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 42.5°C for Quad-Core Intel® Xeon® Processor X5300 Series 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. 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 and 2%. Although designing to Thermal Profile B results in increased TCASE temperatures compared to Thermal Profile A at a given power level, both of these Thermal Profiles ensure that Intel's long-term processor reliability requirements are satisfied. In other words, designing to Thermal Profile B does not impose any additional risk to Intel's long-term reliability requirements. Thermal solutions that exceed Thermal Profile B specification are considered incompliant and will adversely affect the long-term reliability of the processor. Quad-Core Intel® Xeon® Processor 5300 Series Thermal/Mechanical Design Guidelines (TMDG) 27