The 965 is probably the warmest cpu Intel ever made. With the newer core2 duos, you get more speed and cooler cpus. You might be able to upgrade the cpu heatsink if you go with the 965. You can also check starmicro for similar cpus; the 3.4 might give you some performance boost, and it should work with your heatsink. The early dual core cpus actually performed better for many applications. The 805 is one example, but I don't know if it will work with your motherboard. And the $100 for the 965 is no bargain; For about the same money, you can get an e5400 combo deal at Fry's with motherboard that will perform better.