Until x64 3Dmarks and PCMarks and generally most benchmarking programs are actually availble, i'm finding a distinct different in results running within a x64 enviroment and a x32.
Most distinct is the fact that for example.. running within x64 i can score roughly close to 6200 3DMarks with my current system.
However within x32 (xp pro sp2) i can score 10% better (between 6900-7000) ... give or take.... (i'm seeing roughly a 10% difference across all the benchmarks to be precise)
In any case, i'm rerunning a bunch of benchmarks.. curious to see what all you other x64 users are getting for results:
ATM Latest Results:
3DMark06 : 6167:
http://service.futuremark.com/compare?3dm06=202784