[Akuma]

Core speed is only a part of the total performance. Most important is pipelines. The 9800 Pro has 8 while the 9600 Pro only has 4. Next is memory interface. 9800 Pro has 256bit while 9600 Pro only has 128bit. So the 9600 must have a core and memory speed twice that of the 9800 pro to have equal performance.

Also the 256MB 9600 Pro is a POS. While it has more memory than it's 128MB counterpart, it performs worse because they put really shitty memory in there.