Quote Originally Posted by Ughmahedhurtz
http://www23.tomshardware.com/cpu_2007.html?modelx=33&model1=917&model2=880&char t=436

Based on what I see in my labs here with Athlon X2 and Core2duo machines and a general guesstimate based on the charts in the link above, I'd guess you'd see about a 15-20% increase in performance with your setup just from the CPU. Upgrading your memory as you mentioned will also gain you a not insignificant gain. I'd guess with both of those upgrades, you'd see about a 25-30% improvement.

This is ballpark based on my experience in the industry, so don't bank on this.
Id concur with that, especially if you are going from DDR to DDR2 memory.