Intel Core 2 Quad Q9400 or AMD Phenom X4 9950 Quad Core?

[Soleron]

The Intel chip wins, but like Viper1 said, the AMD chip is much cheaper so you should compare it to others in its price range. Clock speed is not an indicator of performance!

Against the Q6600, which is Intel's offering in the AMD price range, the X4 9950 beats the Q6600 in games in most cases:

http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=3344&p=15

This shows the X4 9950 leading in 3 of 4 games.

So, get the AMD chip unless the Q6600 is much cheaper at the time. If you can afford the Q9400, then get that as AMD has no competition in that range.