Our CPU test suite is nicely split into single- and multi-threaded benchmarks and applications. Single-threaded ones first.
You can see the AMD processors scale almost linearly in their 200MHz steps, from X2 4800+ and 4000+ (both 2.4GHz, 1MB L2) to FX-60 (2.6GHz, 1MB), and finally FX-57 (2.8GHz, 1MB). Cache-agnostic on the Netburst core, Realstorm also scales with CPU frequency with the Intel processors.
The performance difference between AMD and Intel here is a measure of the performance of the FPU for the most part, AMD processors having the stronger one when doing lots of 3D-oriented calculations as in Realstorm.
The result graph follows the pattern of the Realstorm results, for the same reasons. The AMD processors generally have the stronger main integer pipe and FPU, depending on the calculation being performed of course.