"The idea [in Crankshaft] is to heavily optimize code that is frequently executed and not waste time optimizing code that is not," the two engineers said. "Because of this, benchmarks that finish in just a few milliseconds, such as SunSpider, will show little improvement with Crankshaft. The more work an application does, the bigger the gains will be."

In the V8 tests, Chrome's canary build was over twice as fast as Firefox 4 current beta and Opera Software's Opera 11 preview. When pitted against Microsoft's Internet Explorer 9 (IE9) beta, Chrome was more than five times faster.

Of course, JavaScript benchmarks aren't the only measure of a browser's speed, a fact that Microsoft has repeatedly pointed out even as it's cited SunSpider results IE9.

Last month, Dean Hachamovitch, a Microsoft executive who leads IE development, as "at best, not very useful, and at worst, misleading. There's more to real world performance than JavaScript."

Users can switch to Chrome canary, which is available only for Windows, by from Google's site.