Valve Benchmarks and Euler 3D Results
Valve Particle BenchmarkThis nice little benchmark created by Valve uses multiple cores to help render particles in complex scenes. The more cores present, the better the performance in this highly parallel workload.

This benchmark is able to take advantage of non-power-of-2 processors, and the X6 products really are able to show off here.
Valve Map Compilation Benchmark
Map creation involves a lot of pre-calculated values for lighting and some effects. This benchmark leverages the extra cores to make the process go faster.

Unlike the previous Valve benchmark, this does not recognize more than four cores. So the X6 parts are out of luck.
Euler3D
This professional level benchmark effectively scales across more cores to simulate air flow over a modeled airfoil.

This benchmark is not really optimized to run on AMD processors, and I imagine that it was compiled using an older Intel compiler which ignores SSE on AMD chips and instead forces the x87 pathway for the calculations. Still, more cores means faster results.