This benchmark is a simulation of the Impact HTML5 game engine in action, and should be pretty indicative of simple HTML5 platformers.
The order that the browsers place in this test is identical on both platforms: IE10, Firefox, Chrome, Opera, and IE9. While the placing order remains the same across OSes, the scores are definitely not the same. IE10, Firefox, and Chrome all enjoy substantially better scores in Windows 8, and even Opera enjoys a moderately higher score.
WebXPRT is a cross-platform HTML5 benchmark framed in the scenario of productivity Web apps. This test includes photo effects and face detection to represent tasks of an image editor, a stocks dashboard with tables and charts, and an offline note app. We used the Consumer Preview 1 build of this benchmark since it still isn't final. While we typically wouldn't do that, unlike almost every other pre-release benchmark we try, this one presented no problems on any of our browsers or platforms.
WebXPRT shows that Forefox is the browser best suited towards office-oriented HTML5-based Web apps, with Chrome taking a very close second place on both platforms. IE10 trails, but still secures a respectable third-place finish, followed by Opera in fourth. IE9 does not compare well to the newer contenders in this benchmark. All of the browsers again perform better under Windows 8.
HTML5 Composite Score
This score is a geometric mean of the Impact and WebXPRT results.
Firefox is the clear winner, though Chrome is not very far behind. IE10 also shows favorably, while Opera is noticeably behind the pack in this particular metric. IE9 is simply out-classed.
Unfortunately, we have no CSS3 tests, since we had to bring back IE9. Fortunately, we can't imagine a reason to test that browser again, so look forward to seeing Kaizoumark alongside our HTML5 benchmarks in the future.
Hear that GPU cooler spinning up? Sounds like it's time for hardware acceleration performance testing in HTML5 and WebGL.