During Microsoft’s MIX conference in Las Vegas, Windows Phone director Joe Belfiore took the stage to demonstrate how well Microsoft’s new Internet Explorer 9 mobile browser can render HTML5 websites. He fired up a device running Microsoft’s new Windows Phone “Mango” update with IE9 installed and hardware acceleration, and then started an HTML5 speed test pitting the Mango device against the iPhone 4 and the Google Nexus S. Belfiore was so confident in the new browser that he gave the iPhone 4 a head start. Nonetheless, IE9 loaded the demo faster and came out on top, having displayed the test at 20 frames per second. It was followed by the Android browser on the Nexus S, which rendered the same demo at 11 frames per second, and then the iPhone 4 at 2 frames per second. This wasn’t exactly an independent test given that it was preformed by Microsoft and likely under optimal conditions, but we are definitely still impressed with what we’ve seen so far â€” let’s just hope the update to Mango goes a bit smoother than NoDo. Hit the jump for the video comparison.