IBM Quad-Core Intel Xeon E5405 44R5630 User Manual

24

Quad-Core Intel® Xeon® Processor 5400 Series TMDG

The thermal profile is a line that defines the relationship between a processor’s case 
temperature and its power consumption as shown in 

. The equation of the 

thermal profile is defined as:

Where:

y

= Processor case temperature, T

CASE

 (°C)

x

= Processor power consumption (W)

a

= Case-to-ambient thermal resistance, ΨCA (°C/W)

b

= Processor local ambient temperature, TLA (°C)

The high end point of the Thermal Profile represents the processor’s TDP and the 
associated maximum case temperature (T

CASE_MAX

) and the lower end point represents 

the local ambient temperature at P = 0W. The slope of the Thermal Profile line 
represents the case-to-ambient resistance of the thermal solution with the y-intercept 
being the local processor ambient temperature. The slope of the Thermal Profile is 
constant, which indicates that all frequencies of a processor defined by the Thermal 
Profile will require the same heatsink case-to-ambient resistance.

In order to satisfy the Thermal Profile specification, a thermal solution must be at or 
below the Thermal Profile line for the given processor when its DTS temperature is 
greater than T

CONTROL

 (refer to 

). The Thermal Profile allows the 

customers to make a trade-off between the thermal solution case-to-ambient 
resistance and the processor local ambient temperature that best suits their platform 
implementation (refer to 

). There can be multiple combinations of thermal 

solution case-to-ambient resistance and processor local ambient temperature that can 
meet a given Thermal Profile. If the case-to-ambient resistance and the local ambient 
temperature are known for a specific thermal solution, the Thermal Profile of that 
solution can easily be plotted against the Thermal Profile specification. As explained