Reference times on my system:
Firefox 3.5.5/6: ~3100ms
Firefox 3.5.5/6 (w/o Firebug)* ~2407ms
Firefox 3.6B4 (w/o Firebug)** >5xxxms (differs wildly, from around 5 to 10 seconds)
Google Chrome 3.0.195.38: ~ 300ms on the first run, then ~200ms. probably because the first time the code has to be JITted?
Safari 4.0.4: ~ 340ms
* i just installed 3.5.6. it's about the same speed as 3.5.5 (with FB). both are a bit faster w/o FB (as expected).
still, why is the difference the tracing JIT makes so small? what am i missing?
** for some reason, 3.6b4 seems to be *a lot* slower. about:config jit is enabled.
Opera: not yet tested
IE: heh.