Hopefully someone has the answer to this, ever since we upgraded to SP6 we've been having multiple abends on a server. As part of troubleshooting we ended up disabling Hyperthreading in the BIOS, this does seem to have fixed the abends. The interesting part is that before disabling HT the server saw 4 CPU's, which makes sense since it has a single Dual core CPU (2 Cores and HT on each core). After disabling HT (Not Dual Core, there is no option in the BIOS for that) the server only sees one.

The question is, is this normal ? And will the server still utilize both cores ? Or does this become a waste of money ?

I also went to another new DC server that is still at SP5, and updated the PSM (psm7) on it, and see the exact same result there.