Hardware acceleration is a broad term used to describe different things and implementation quality still matters (i.e. does it do everything from format decoding to color conversion, scaling, compositing, etc. and are any individual steps combined?).<p>Every time I&#x27;ve done that comparison, Flash has used significantly more CPU for the same file. It&#x27;s possible that they&#x27;ve finally managed to get close on the right combination of hardware, OS, and driver versions but given how regularly I still see people talking about huge improvements after uninstalling Flash, I&#x27;m skeptical that this is the most common experience.<p>Similarly, hardware acceleration was not a given in the past and since there&#x27;s still plenty of buggy hardware and drivers out there, both Flash and all major browsers have software playback paths and there&#x27;s even more room for variation there. It&#x27;s not as bad as when people were comparing Flash&#x27;s scalar code to Apple&#x27;s well-optimized SIMD but if you disable hardware acceleration you can still see major deltas because Adobe was never willing to invest the same amount of effort in optimization. This hit Flash more because there were design constraints which caused it to silently disable HW acceleration and developers using fast desktops often didn&#x27;t notice that happening.<p>Flash was never better than the native AV frameworks on Windows or OS X. What it offered was convenience during the period when you couldn&#x27;t rely on everyone having support for a modern video codec and, of course, being able to do things other than simply play back a video file.