Google yesterday released the first beta of Chrome 10, touting the new version's faster JavaScript engine.

According to tests run by Computerworld, Chrome 10 is 64% faster than its predecessor on Google's own V8 JavaScript benchmarks. Google shipped the stable version of Chrome 9 earlier this month.

Google maintains three separate "channels" of Chrome -- stable, beta and dev -- that denote increasingly rougher-edged editions.

But in another JavaScript benchmark -- WebKit's widely-cited SunSpider -- Chrome 10 beta was no faster than Chrome 9. WebKit is the open-source project that develops the browser engine by the same name; both Chrome and Apple's Safari rely on the WebKit engine.

Google debuted a new optimization technology, dubbed "Crankshaft," in December when it added it to Chrome's V8 JavaScript rendering engine. Yesterday's release was the first beta build to feature Crankshaft.

Computerworld ran Chrome 9 and 10 three times each through V8 and SunSpider on a Windows 7 PC, then averaged the three scores.

Chrome 10 beta was 64% faster than Chrome 9 in V8, but only a statistically-insignificant 0.1% faster in SunSpider.

Two months ago, Google engineers explained why SunSpider scores for a Crankshaft-equipped Chrome show little, if any, improvement over browsers that don't include the optimization technology.

"The idea [in Crankshaft] is to heavily optimize code that is frequently executed and not waste time optimizing code that is not," said the engineers. "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."

Other additions to Chrome 10 beta include hardware-accelerated video, a change to how the browser's options are displayed, automatic password synchronization and a new security feature that automatically disables older plug-ins.

The new hardware acceleration shifts some of the video load onto the computer's graphics processor, thus reducing the impact on the system's CPU. Google said the new technology was still under construction, and the feature in Chrome 10 beta was a "preliminary implementation."

Passwords are now synched by default with Chrome's integrated synchronization tool, which also keeps bookmarks, extensions, apps and other settings consistent across copies of Chrome running on different machines.

The browser now also automatically disables out-of-date plug-ins to keep users safer -- plug-ins have become a major target of hackers, who aim exploits at vulnerable versions. Nearly 80% of the browsers used by consumers require patching, a security firm said this week, with most of the unfixed flaws residing in plug-ins such as Oracle's Java and Adobe's Reader.

Mozilla's Firefox includes similar protection, warning users when they're about to use an obsolete plug-in.

Users can download Chrome 10 beta from Google's site.

If Google keeps to its usual six-to-eight-week schedule, most if not all of the features in the beta will make it into the stable version in late March or early April.

Chrome 10 beta was 64% faster than the "stable" edition of Chrome 9 in Google's own V8 JavaScript benchmark tests. (In V8, higher scores are better.)

Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer or subscribe to Gregg's RSS feed . His e-mail address is gkeizer@computerworld.com.