Lots of stories making the rounds that the JavaScript speed of the new iPhone 3GS is even faster than Apple had claimed. Most of the stories originate from this one from Medialets, but it’s simply not true the performance is faster than Apple claimed.

JavaScript speed is very impressive. However, if you compare Medialets’ results with those Apple presented during the WWDC keynote, you’ll see they’re essentially the same. Let’s take a look:

I’d say Medialets’ findings of 133/49/17 for the iPhone 3G-os2/3G-os3/3GS match up very well with Apple’s reported results of 126/43/15. Apple’s numbers are a bit better, but not excessively so. It’s clear that all Medialets has done is confirm Apple’s stated speed claims in this area.

This is a huge speed improvment, and I’m not trying to diminish it, but Apple’s claim of “twice as fast” was a generic one regarding the 3GS in general, whereas their JavaScript claims were very specific. Medialets has shown they were accurate, not underrated.