There's been a lot of discussion on the blogsphere over the last few weeks due to Steve Jobs being quoted as saying one of the reasons Apple won't support Flash video on the upcoming iPad was due to Flash being a "CPU Hog". Apple's workaround to Flash video is to use HTML5 and that encouraged some to even suggest that HTML5 would kill off Flash, which couldn't be further from the truth.
But rather than debate this topic, Jan Ozer, a technical writer for StreamingMedia.com and encoding guru, decided to spend the time to actually test Flash versus HTML5 and published all of his testing methodology and results on his blog. While you should check out his entire post to see all the details, here are some of the highlights of what he says.
When it comes to efficient video playback, the ability to access hardware acceleration is the single most important factor in the overall CPU load. On Windows, where Flash can access hardware acceleration, the CPU requirements drop to negligible levels. It seems reasonable to assume that if the Flash Player could access GPU-based hardware acceleration on the Mac (or iPod/iPhone/iPad), the difference between the CPU required for HTML5 playback and Flash playback would be very much narrowed, if not eliminated.
Overall, it's inaccurate to conclude that Flash is inherently inefficient. Rather, Flash is efficient on platforms where it can access hardware acceleration and less efficient where it can't. With Flash Player 10.1, Flash has the opportunity for a true leap in video playback performance on all platforms that enable hardware acceleration.
Apple complaining about Flash being a CPU Hog while not exposing "the appropriate hooks" to enable Adobe to access hardware acceleration seems disingenuous at best. To be fair to Apple, though, the iPad related timing was unfortunate, with the bulk of the development work done under the shadow of Flash Player 10.0, which didn't offer hardware acceleration other than full screen on any platform and was clearly less efficient than the HTML5-based approach Apple adopted. Now that Adobe has proven the concept on Windows, perhaps Apple will cooperate with Adobe to make hardware acceleration on the Mac, iPad and future devices happen. If they choose not to, however, they should quit pointing fingers at Flash.