Early JavaScript benchmarks from iPhones running a beta of iPhone OS 3.0 suggest the new version will bring big speed gains to web apps running in Mobile Safari, even on existing iPhone hardware. With an average 3x speed improvement, some individual benchmarks reveal as much as an 16x increase in execution speed over the existing version of Mobile Safari in iPhone OS 2.2.

Likely leveraging the new Nitro (n?e SquirrelFish Extreme) JavaScript engine currently in the Safari 4 beta, the new version of Mobile Safari can really plow through some JavaScript code. The first set of data we have comes from developer Wayne Pan, who ran a simple set of benchmarks developed by Icon Factory's Craig Hockenberry. "iPhone 3.0 definitely has something, whether it’s SquirrelFish or Nitro, but it’s 3-10x faster than iPhone 2.2," Pan wrote on his blog.

This comparison is from a series of five simple benchmarks—each test runs 10,000 times—from iPhone developer Craig Hockenberry.

The second set of data shows a comparison between iPhone OS 2.2.1 and the iPhone OS 3.0 beta running the WebKit team's SunSpider benchmark. According to our sources, the 3.0 beta still has some stability and speed issues, so that makes these results that much more impressive. While the overall average gives the iPhone 3.0 beta a 300 percent speed advantage, some of the individual tests show 6x, 8x, or even 11x improvements—the bitwise "AND" function even runs 16x faster than in the current version of Mobile Safari.

This is the series of benchmarks from WebKit's SunSpider benchmark suite. There are some pretty impressive gains in certain types of functions.

There's no doubt that iPhone OS 3.0 will see quite a bit of polish before it's released this summer. If the updated hardware has improved processing power as predicted, the gains may be even more impressive. Still, even a 3x speed increase will be welcome to existing iPhone owners updating to the new OS—the speed will be beneficial for both web-based applications and general surfing.