Yeah, the difference is about the same as AMD's Phenom II compared to i7. You won't notice a difference unless you have a very high end graphics (assuming you are talking about the yorksfield C2Qs) or are looking for some future-proofing. If i5/i7 is out of your budget/needs then go for AMD. LGA 775 is a dead socket, as monkey said, and Phenom II is no slouch for gaming.