I am far from an expert but my observation is that the newer 64 class is running faster at the cpu ghz of the XP's. If the price of those 2 cpu's are close, get the 3200 or down the road you may wish you had.,But at least max out the limitation of the mobo. And the XP series doe run warm, I have the vent closed in my computer room, my pc warms the room up just fine. If given the choice and had the money, I'd of got the barebones 3700 off tigerdirect.