The battle between HTML 5 and Flash wages on with the discovery of an interesting report comparing the CPU usage of HTML 5 and Flash on both Mac and Windows platform. In the midst of all the smack talk about Flash, Flash was presumed to be a CPU hog that chokes your system to the point of death. A series of measurements performed by video compression guru Jan Ozer reveals that Flash may not be as much of a CPU killer as previously thought and that, in some cases, HTML 5 is the culprit that causes CPU overload. Ozer tested HTML 5 and Flash on a Mac using Safari, Chrome and Firefox and on a Windows machine using Safari, Chrome, Firefox and Internet Explorer.
The results show that Flash CPU utilization is much higher on a Mac with Flash 10.1 gobbling up 32.07 CPU % points when using Safari, 42.07 when using Firefox and a whopping 49.79 when using Chrome. Flash 10.1 was much gentler on the Windows machine with CPU utilization topping out a reasonable 14.63 CPU % points when using IE and dropping as low as 6% when using Firefox. HTML 5 results were all over the chart with HTML 5 consuming a mere 12.39 CPU % points in Safari, presumably due to the built-in H.264 decoding found in the Apple browser, while at the same time, chomping down a staggering 49.89 in the Mac version of Chrome. The Windows platform fared a bit better with Chrome using 25.66% CPU points when rendering HTML 5 content. In the end, Flash is markedly better on Windows (which we already knew) and HTML 5 shines in the Safari for the Mac but why is there such a disparity between the two platforms? Hit the jump to find out.
Ozer believes that one of the deciding factors influencing CPU utilization by Flash is the presence (or absence) of GPU hardware acceleration. On the Windows platform where GPU hardware acceleration for Flash is often written into the drivers for video cards, Flash performance is exceptional while HTML 5 is only mediocre. On the Macintosh, HTML 5 performance is boosted by the presence of H.264 decoding built into Safari for the Mac while Flash performance is significantly worse as Mac OS X does not provide access to the APIs necessary for GPU acceleration. If Apple opened up the appropriate hooks for Adode to tap into, CPU utilization by Flash could be reduced significantly and its performance would rival that of HTML 5. So yes, Steve, Adobe Flash is a CPU hog but only on the Mac and one of the reasons is because you let it be.