HP Z8 not recognizing memory on CPU 1

[machish]

I was trying out different CPU's on my Z8 G4.

At some point, all the DIMM's associated with CPU 1 were no longer recognized.

When they are all plugged in to the slots next to CPU 0, the system detects all of the memory.

But any time I plug anything in to the slots next to CPU 1, they are ignored. (BIOS info screens say that there is nothing there, even though there is.)

As a result, the NUMA system is very non-uniform, since CPU 1 has no local memory, and it all has to go to CPU 0.

I did run the system for a little while with only CPU 0 installed (nothing in the CPU 1 slot) when I was waiting for parts. Could this have potentially damaged something? Or gotten dirt somewhere? Or is there a BIOS setting that might have somehow got tripped up?

Thanks!

[content removed]

[machish]

Removing CPU1, ensuring that there was no dust on the pins, and replacing it "solved" the issue, and DIMMs in all slots are now recognized.

However it still looks like it's more expensive to access the local memory from CPU1. Is that expected on Z8's?

$ coreinfo -m

Coreinfo v3.6 - Dump information on system CPU and memory topology
Copyright (C) 2008-2022 Mark Russinovich
Sysinternals - www.sysinternals.com

Approximate Cross-NUMA Node Access Cost (relative to fastest):
00 01
00: 1.0 1.3
01: 1.2 1.5