I've googled this, but I seemd to get a load of people who didn't know themselves what they were talking about, all wondering what it is themselves. I guess it must ave been the terms I used....

Anyway, what exactly is the "CPU Spread Spectrum" option in my BIOS for? IE, what does it do, and how does it do it (how does it work?)

It isn't documented in your manual?
(tried to download it, but it would've taken me about 30 min, since they seem to be bandwidth starved!)

Spike from ac2? just wonderin hehe

Stragely enogh, the manual doesn't have ANY BIOS options documented (Crazy, I know!). All it has is information specific to the mainboard itself.

Spread spectrum means that the shapes of the signals running on your mobo are made less agressive so that the EMI generated by them fits into some standards. If you are having problems with inteference then you can turn it on. Tweaking sites on the web say that this is a performance loss though.

I think spread spectrum may be frequency modulation of the cpu clock rate (and hence all clock driven mainboard components), so that any EMI interference generated is not always at the same constant frequency, but instead is spread over a small band of frequencies, therefore reducing problems with equipment that may be particularly sensitive to certain fixed frequencies. It won't eliminate EMI, but it should reduce the effects on other equipment.