Edit: Disregard this post, my performance issues have been resolved with beta driver version 8.54. See these threads:
4870x2 fix with 8.9betas(ver.8.54)...bog screenshots...and 8.54 driver install guide
4870x2 8.54 drivers = Wow Performance in COD4!!!!
4870x2 fix with 8.9betas(ver.8.54)...bog screenshots...and 8.54 driver install guide
4870x2 8.54 drivers = Wow Performance in COD4!!!!