Octane delivers a score that aims to rank browser performance across all platforms, but it's hard to place real-world meaning to the results until we spend more time observing how they line up with our own feelings of browser performance. For what it's worth, in our unscientific battery of tests on a 2011 Macbook Air Chrome version 21 earned an average of about 9,700, while Safari 6 earned an average of about 7,000 (higher is better).
Head on over to the Octane page if you're interested in checking the tests out yourself. Google offers a breakdown of the suite that details what they're measuring at every step.There's also a compatibility chart that offers a birds-eye view of some known issues with the benchmark; the Android browser fails on a pair of the new tests, while both Safari and Chrome fall victim to iOS restrictions. On the desktop end, Internet Explorer 9 is currently incompatible.