Sunspider benchmark (Win XP, dual core machine):

Opera (v10.53): 299.8ms +/- 1.0%

Safari (v5): 314.2ms +/- 1.7%

Chrome (v5.0.375.55): 326.6ms +/- 7.9%

Firefox (v3.6.3): 716.4ms +/- 1.7%