I have an odd issue, but it doesn't seem to be hindering my Linux box.
I just built a new box last night, usuing an Intel 865PERL single processor board, and a 3.0 ghz P4 cpu with 1GB DDR400 RAM. The board and chip have 800mhz fsb and support "hyperthreading" (whatever that is).
Well, before I set it up, I put in Knoppix (Debian-based LiveCD) CD to test the hardware, and noticed it booted as a dual-proc (smp). Huh. I didn't pay too much attention to this until I installed Fedora Core 1, and noticed it default booted to an smp kernel. It runs great on smp so far, but there's only a single processor in the box.
Any clues as to what Linux is seeing? Will leaving it as smp screw up anything down the road?