I was upgrading one of our ESX servers (HP dl580 G2) last week and ran into a little problem. I would get Kernel Panic errors everytime the machine booted after install. The exact error was: Mod: 4670: vmkernel not loaded: cannot PSOD.
I did some searching and found this: Required MPS Table BIOS Settings for ESX Server on ProLiant.
I made the recommended changes and my server worked perfectly. I also checked one of my new servers (HP dl585 G2) and found that it is pre-set to Full Table APIC with no OS selection option.
Funny thing is that the dl580 had an ESX problem for about a year that was probably related. That machine had ESX 2.5.2 installed. ESX only detected 1 processor and no hyperthreading. I played around with it, but never fixed it because it was mainly used as a test server. Thankfully it’s all working now.