Lenovo Intel Xeon E5520 67Y0011 Manuale Utente

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Thermal/Mechanical Design Guide

By averaging DTS over PECI, thermal solution failure can be detected and a soft 
shutdown can be initiated to help prevent loss of data.

Thermal data is averaged over a rolling window of 256mS by default (X=8):

AVG

N

 = AVG

N-1

 * (1 – 1/2

X

) + Temperature * 1/2

X

Using a smaller averaging constant could cause premature detection of failure.

The Critical Temperature threshold generally triggers somewhere between PECI of 
-0.75 and -0.50. To avoid false shutdowns, initiate soft shutdown at -0.25.

Since customer designs, boundary conditions, and failure scenarios differ, above 
guidance should be tested in the customer’s system to prevent loss of data during 
shutdown.

Intel® Turbo Boost Technology (Intel®

 

TBT) is a new feature available on certain 

processor SKUs that opportunistically, and automatically, allows the processor to run 
faster than the marked frequency if the part is operating below its power, temperature 
and current limits.

Heatsink performance (lower Ψ

CA

) is one of several 

factors that can impact the amount of Intel® TBT frequency benefit. Intel® TBT 
performance is also constrained by ICC, and VCC limits.

Increased IMON accuracy may provide more Intel® TBT benefit on TDP limited 
applications, as compared to lower Ψ

CA

, as temperature is not typically the limiter for 

these workloads. 

With Intel® TBT enabled, the processor may run more consistently at higher power 
levels (but still within TDP), and be more likely to operate above T

CONTROL

, as 

compared to when Intel® TBT is disabled. This may result in higher acoustics. 

With Intel® TBT enabled, processors with dual thermal profiles (described in 

, have greater potential for performance delta between Profile A and 

Profile B platforms, as compared to previous platforms.

Under fan failure or other anomalous thermal excursions, Tcase may exceed Thermal 
Profile B for a duration totaling less than 360 hours per year without affecting long term 
reliability (life) of the processor. For more typical thermal excursions, Thermal Monitor 
is expected to control the processor power level as long as conditions do not allow the 
Tcase to exceed the temperature at which Thermal Control Circuit (TCC) activation 
initially occurred. Under more severe anomalous thermal excursions when the 
processor temperature cannot be controlled at or below this Tcase level by TCC 
activation, then data integrity is not assured. At some higher threshold, THERMTRIP# 
will enable a shut down in an attempt to prevent permanent damage to the processor. 
Thermal Test Vehicle (TTV) may be used to check anomalous thermal excursion