Is browser performance affected by OS, CPU and the amount of RAM available?
Good test, but it would be nice if you did some testing on a more commonplace computer- something like an ordinary XP computer with 1 or 2 Gb of ram. This would be more meaningful to most of your readers- Vista is used only by a small minority of computer users at this time. I question the value of the test to most computer operators when the testing is conducted on Vista, and probably with a VERY high powered machine comparatively speaking. Would such a test have similar results on a more ordinary machine? Not to pick nits, I am simply wondering what applicability your testing would have to most users.
My initial testing was done on a 3.2GHz quad-core system with 2GB of RAM on Vista SP1 32-bit. A high power system, but since I was comparing the browsers on a like-for-like system, it didn't seem to matter. Surely on a slower system the only difference would be that the overall scores would be higher indicating a slower system.