Proliant 5500 dual Xeon only 1 CPU appears in OS

[barf_nz]

Please help me wipe the dust off this old Compaq! It's survived 10 years I think another 10 is not impossible!

I'm trying to make the second processor show up to the OS (GNU/Linux) on a Proliant 5500 (Dual Xeon @ 450MHz, 1GB RAM). Only 1 CPU appears despite two (and the associated voltage regulator boards) being installed.

I've been through SmartStart 5.50 was the most recent version supported, and installed the OS using the documented method. However, I still can only get one processor to appear even though my kernel is compiled with SMP.

Is this something anyone has seen before? Searching the posts here does indicate the issue is somewhat common but I cannot find a solution.

[Johan Guldmyr]

Whoa, 5500 :) Nice find.

Are both CPUs seen in POST? Maybe there's some BIOS settings that relates to this?