Thank you for the response.  What about the 5400 series Xeon which are present in most 1950/2950 Generation III poweredge servers?

Hi Bob,

 

Here is a list of supported processors and if they allow Demand Based Switching:

 

 

Xeon 5160    Yes
Xeon 5130    No
Xeon 5110    No
Xeon 5150    Yes
Xeon 5148LV  Yes
Xeon E5310   No
Xeon E5320   Yes
Xeon E5335   No
Xeon E5345   Yes
Xeon X5355   Yes
Xeon X5365   Yes
Xeon L5310   No
Xeon L5320   No
Xeon L5335   No

If your aim is to keep power consumption to a minimum, then you want a 5400 series processor. An L series processor has the lowest Thermal Design Power, then E series, then X series has the highest consumption - so L series would be the most preferable of the three.

 

The Intel Processor Finder (click) will do the job for you - select Intel Xeon Processor, then filter on 45nm Manufacturing Technology (only the 5400 series is 54nm), 1333MHz FSB (1600MHz FSB parts are for a different chipset that I believe doesn't have features typically needed in a server) and select Demand Based Switching in the supported features.

 

I believe you'll get everything displayed apart from the 2.00GHz parts - Intel's literature for the 5400 series says that they don't support Demand Based Switching.

 

 

You will need to upgrade the server to the latest 2.3.1 BIOS for Demand Based Switching to work correctly; there's bugs in the ACPI DSDT in 2.2.6.