4870 mac edition benchmarks

I haven't found any benchmarks of the new 4870 for mac. I'm mainly curious of performance of games in windows. ex. Crysis, Far Cry, Left 4 Dead. @ 1920 by 1200 with varying AA and AF. I've heard that the 4870 is actually slower than the ATI spec (correct me if I'm wrong about that). If someone has any of these numbers please post them. I've ordered a 4870 for my early '08 mac pro and would like to know if it is substantially faster than my 8800 GT.