We saw performance improvements varying from 7-10% for ATI hardware, with the result varying depending on the card used and the resolution tested. Obviously this isn’t as significant as some enthusiasts were hoping for, but at the same time, you could also argue that this improvement is equivalent to a 100-200MHz clock frequency boost (assuming equal architectures). That’s not bad for a “free” upgrade. For whatever reason, NVIDIA GeForce 6 cards didn’t fare as well in our testing.
Perhaps it’s due to the beta nature of the drivers we used, or the condition of CryTek’s patch itself. For instance, we encountered numerous visual anomalies in multiple levels from the game once HDR was enabled. After a few hours of experimentation we finally gave up. We also noticed visual quirks in a few other levels without HDR turned on. It’s possible that NVIDIA’s driver could be causing these problems, or it’s also possible that CryTek’s patch is the culprit.