I have a pair of NW6.0SP5 servers in a cluster. Both are DL580G2's with 4 real processors, no hyperthreading. It appears a previous admin commented out CPQACPI.PSM in STARTUP.NCF and both servers appear to be running off one processor.

I have read that as 6.0 progressed CPQACPI.PSM was no longer maintained and is not necessary, and that I should load ACPIDRV.PSM instead.

Why would someone disable this?

Is my research correct that I should use ACPIDRV instead?