With all eyes on the iPad 2 that becomes available tomorrow at 5 p.m. in each time zone, Apple has released its iOS 4.3 update for the first-gen iPad, iPhone 3G S, non-Verizon Wireless iPhone 4, and recent iPod Touch models.

Macworld's sister title InfoWorld.com ran the Futuremark Peacekeeper browser tests on a first-gen iPad with iOS 4.2 and with iOS 4.3 to see if Apple's claims of a turbocharged JavaScript engine were justified.

The answer is yes. The test ran 18 percent faster under iOS 4.3 than under iOS 4.2 on the same iPad, the 64GB Wi-Fi + 3G model, with a score of 508 versus 430. (Larger numbers are better.) Those results bode well for the iPad 2, which sports a dual-core A5 processor versus the iPad 1's single-core A4.

For comparison, a single-core Verizon iPhone 4 running iOS 4.2.6 (there is no 4.3 update for this model) scored 482, while a dual-core Motorola Mobility Atrix 4G Android 2.2 smartphone scored 662 and a dual-core Motorola Xoom Android 3.0 tablet scored 897. A quad-core i7-based, 2011-model MacBook Pro 15 running Safari 5 scored 2812, and a prototype Chrome OS "Chromebook" laptop scored 1310.

Of course, synthetic tests such as Peacekeeper don't necessarily reflect real-world usage, as each website has very different code and thus may not stress all the functions in the Peacekeeper's repertoire. But such tests do provide a good baseline for comparing media-rich and JavaScript-heavy sites.