Go with the X2 dual core ... You won't regret it, it is a waste of money these days to buy single core ... they will become extinct by the end of this year ... there are many people taht don't believe in that dual core hype but when they try it, they don't go back. They run really cool, i easily overclocked mine to run at 4400+ and still running idle at 40C with the factory fan!! ... right now you can run many applications with no lag whatsoever but once Vista comes out, the gain in performance will be huge once they make full use of dual core. There is no comparison!!