Firefox 3.0 RC 1 takes the lead on speed

The Mozilla dev team claims to have squeezed more performance out of Firefox 3.0. The betas were fast, so has the team been able to get more out of their code?

Over the past few months I have benchmarked several incarnations of Firefox 3.0 beta. My last benchmark of Firefox 3.0 (using the SunSpider JavaScript benchmark), which looked at Beta 5, showed the browser to be the fastest of the pack, comfortably beating all the competition.

SunSpider JavaScript benchmark

So, how does Firefox 3.0 RC 1 compare? This latest run of tests was run on the same hardware and software platform as previous tests (to make sure nothing had changed we re-ran some of the browsers to check that we got the same results). Also added to the listing were Opera 9.27 and Opera 9.50 Beta 2.

Here are the results:

As you can see the difference between Firefox 3.0 RC1 and Firefox 3.0 Beta 5 is only a few milliseconds, but over repeated runs the lead it held over the other browsers remained consistent.

What's really amazing (and a little hard to take in) is that Firefox 3.0 is now nearly ten times faster at processing the SunSpider benchmark than IE7 is.

ACID 3

I also took the opportunity to put each browser up against the ACID 3 CSS compliance test. In this latest set of tests Opera 9.50 Beta 2 has taken the crown from the previous leader, Safari 3.1.

Thoughts?