Intel X3350 Design Guide - Page 60

Thermal Solutions 7.5.2 NEBS Thermal Profile Processors that offer a NEBS thermal profile are specified in the Intel® Xeon® Processor C5500/C3500 Series Datasheet). NEBS thermal profiles help relieve thermal constraints for Short-Term NEBS conditions. To help reliability, processors must meet the nominal thermal profile under standard operating conditions and can only rise up to the Short-Term spec for NEBS excursions (see Figure 7-6). Short-Term is clearly defined for NEBS Level 3 but the 360 hours per year limit is a key consideration. Note: Fan speed can be decreased and case temperatures can be allowed to rise above the thermal profile if the processor is below Tcontrol (see Section 7.6.1). Exceeding the thermal profile at these lower temperatures is not considered a risk to reliability. Figure 7-6. NEBS Thermal Profile Note: 1.) The thermal specifications shown in this graph are for reference only. See the Intel® Xeon® Processor C5500/ C3500 Series Datasheet for the Thermal Profile specifications. In case of conflict, the data information in the Datasheet supersedes any data in this figure. 2.) The Nominal Thermal Profile must be used for all normal operating conditions, or for products that do not require NEBS Level 3 compliance. 3.) The Short-Term Thermal Profile may only be used for short-term excursions to higher ambient operating temperatures, not to exceed 360 hours per year as compliant with NEBS Level 3. 4.) Implementation of either thermal profile should result in virtually no TCC activation. 5.) Utilization of a thermal solution that exceeds the Short-Term Thermal Profile, or which operates at the ShortTerm Thermal Profile for a duration longer than the limits specified in Note 3 above, do not meet the processor thermal specifications and may result in permanent damage to the processor. August 2010 Order Number: 323107-002US Intel® Xeon® Processor C5500/C3500 Series and LGA1366 Socket Thermal/Mechanical Design Guide 60