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 126.96.36.199: ~ 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.