I have a single core Venice 939 3200 in an ABIT AN8 SLI with 2x1GB G.Skill memory. Does it make more sense to upgrade to a C2D or would I be served better by just getting one of the X2 chips from AMD ? I can't spend much on this, thus leaning towards upgrading the CPU only. Newegg has the X2 3800 OEM Toledo (939) for $89, this would seem to fit the bill. Questions on that come up as to whether I could use the stock AMD cooler that came with my 3200, and whether I would have to do any overclocking to realize the potential here. My board does not seem to overclock well, at least when I only tried to OC current CPU to 2200Mhz, I kept having funky problems. C2D would be better but the money would have to be quite more too, as I'd have to replace mobo, cpu and memory. Or should I go for one of those AsRock mobos supporting DDR 400 ? I guess I'm confused on how to spend my money best, knowing it's not much I've got for an upgrade here...
TDP on the Toledo is 110W, and only 67W for the Venice, so I'd think you'd probably need a new heatsink as well.
I wouldn't try for one of the Asrock boards. I know you'll be able to re-use your RAM, but you're going to be stuck having to make this same decision in another 6 months, and you'll have a motherboard and RAM you can't re-use.
Dropping in the X2 is the better option here, as it's cheaper and easier.
Personally, I'd try to be happy with what you have now, and save that cash for a replacement. You may be able to get some extra money by eBaying your old parts, too.