CineBench
CineBench is a great rendering test; with its high quality built-in benchmark image and multi-threading support it is one of the better ways of showing potential improvements from multi-core processors.
Not surprisingly, the stock D 805 fares poorly - it does beat the higher speed single core processors, but can't beat other dual core results. The Sempron does quite well in relation to the D 805.
Once overclocked, we get MUCH better results, and it actually ends up in the middle of the pack - beating a stock X2 4200+, D 840, X2 3800+ and D 820.
POV-Ray 3.7b
POVRay does better with Intel processors than AMD processors. The stock D 805 does very well, and the overclocked D 805 gets the second and third best results. The P4 670 comes in on top, which is quite frankly puzzling - the only reason I can think of for this is that the compiler used for building PovRay has excellent Intel-specific optimizations. The Sempron's performance is absolutely abysmal.