yes. it would, and yes, 2 gigs of PC3200 has more performance than 1 gig of PC4000

well theres 2 gig of PC4000 and 1 of PC3200 so am i just slowing myself down or is there a speed benefit to having that 1 gig of 3200 in there?

No. Actually, i just looked it up. Your motherboard supports dual channel memory. but having different size dimms will make it run in single channel mode. And your motherboard supports up to PC3200 so it wouldnt run at PC4000 speeds. I recommend buying some new DDR-400 (PC3200). Get 2 sticks of 1gig, so you have dual channel, and 2gigs

well thx for the advice i'll have to get around to doing the memory thing but right now i want to put in my new processor

our welcome. Oh, and when you do buy the memory, i recommend this stuff
PQI Power Series 2GB (2x 1GB) DDR-400 Dual Channel Memory Kit
I have used it in the past and it works very well, and is very stable

Oh and marked as Answered