Assuming my cpu is dead, and I think it is, I'll need another. I'm now using an XP 1800+. I don't overclock. How much of an increase will I see in performance going to 2000, 2200, 2400? I know AMD just dropped prices on 2100 and lower. The other question is my new mobo supports up to DDR400. Should I upgrade my ram and again what gains will I see? I currently have 512 PC2100.

You will not see much of a performance increase between the 1800(1.533 Ghz) and even the 2400(2 GHz).
In order to notice a performance difference between CPU,s, there has to be a ratio of approx. 2:1 between their speeds.
I would go with the one that's giving the most bang for the buck, which appears to be the 2100 according to Pricewatch.


However, you may see more of a performance increase with the DDR 400 vs. the PC2100.
But it would be ashame not to put 512MB of good, fast RAM to use.

Thanks for the great answer, Ski, oh master greek :D

I agree, the jump in memory speed should be noticeable. But, and I agree also, no need to spend money where it's not really needed.

Personally, if it were me, I would stay away from the 2100+. I believe it to be one of the hottest running XP chips there is. And you don't want heat. Maybe a 2200+ would be better.

For me, my 1900+ does a fine job and is reasonably priced right now.

If all you want to do is have a working system that will do what you want it to do, you would probably be fine with the 1900+ or 2200+ and keeping your PC2100 for awhile longer.