both chips are just refined versions of the original 9800 and 5900 , both can overclock to the sky and both are 500 USD.........
they both are about the same speed.. 5950 is faster for OGL as usual and the 9800 is faster for all DX games [ except C&C : G at 1600x1200 and Halo at 1600x1200 ] . Both aren't worth the money and both have dropped the price of the predecessors to about 250-300 USD . If it weren't for the usual bad drivers the radeon would be a clear winner because of the features, but they both are on equal footing .
Cat 4 will either lead ATI to victory or leave it struggling for 2nd place .