I ran across http://webkit.org/perf/sunspider-0.9/sunspider.html while surfing the web today.  Unfortunately, I lost track of the original location that I found out about it.  Too bad, because that person had put up some nice graphs of the performance on a couple machines.

I ended up giving it a try on the machines we have around the office (and one from home) and found the results very interesting.  I'm only going to put the "final" times for each combo (and the percent difference between best and worse of 5 runs) since that's all that really matters!  :-)

Sun v250 (Dual UltraSPARC IIIi 1.28ghz, Solaris 10U4) - Mozilla 1.7 = 47576.2 (0.2%), FireFox = 55480 (15.4%, while throwing multiple errors)

Apple PowerBook (PowerPC G4 1.67ghz, Mac OS X 10.5) - Safari = 27014.6 (0.6%)

HP server (Dual PIII 1.13ghz, Windows 2003R2) - Internet Explorer 7 = 131796.6 (1.9%), FireFox = 64158.8 (9.7%, once again throwing multiple errors)

Whitebox/Asus "toaster" (AMD Sempron 2.0ghz, Solaris x64 10U4) - Mozilla = 48648 (.3%), FireFox = 29454 (0.7%)

Whitebox/Intel (Intel P4/HT 3.0ghz, Windows XP SP2) - Internet Explorer 7 = 45330 (.5%)

Interesting to see that the best performer was the Apple/Safari combo.  No surprise about the worst performer being the ancient PIII server.  Other surprises though were with the Solaris machines.  Quite surprised that FireFox threw errors on BOTH during the tests!  Also interesting to see the UltraSPARC/Mozilla combo outperform the Sempron/Mozilla combo.  I had top running during this and it really only seemed to use one processor, so I would have expected the higher ghz Sempron to win that battle!