Currently my PC has a Athlon XP 2700+ t-bred core running at ~2.4 ghz. I am not sure but I might want to upgrade to a 64 bit system. The processor I might buy is a Athlon 64 3000+ at ~2.0 ghz (its the only socket 754 Athlon 64 that I can find with SSE3 support). I know I need a new motherboard and all that junk but, should I upgrade? How much more of a speed boost would I notice?