Intel Xeon X3440 BX80605X3440 Manuale Utente

Thermal/Mechanical Specifications and Design Guidelines

59

• When DTS  i

s  a

bove  T

CONTROL

, FSC algorithms will use knowledge of T

AMBIENT

 and 

Ψ

CA

 versus RPM to achieve the necessary level of cooling.

This chapter will discuss two implementations. The first is a FSC system that is not 
provided the T

AMBIENT

 information and a FSC system that is provided data on the 

current T

AMBIENT

. Either method will result in a thermally compliant solution and some 

acoustic benefit by operating the processor closer to the thermal profile. But only the 
T

AMBIENT

 aware FSC system can fully use the specification for optimized acoustic 

performance.

In the development of the FSC algorithm it should be noted that the T

AMBIENT

 is 

expected to change at a significantly slower rate than the DTS value. The DTS value will 
be driven by the workload on the processor and the thermal solution will be required to 
respond to this much more rapidly than the changes in T

AMBIENT

.

An additional consideration in establishing the fan speed curves is to account for the 
thermal interface material performance degradation over time.