20% sounds good, but unless versions 5, 6 and 7 also had 20% improvements, it would still be slower than the current version of Chrome on canvas stuff.
For the relatively simple canvas rendering I'm doing, I can watch Firefox chugging along at 10fps struggling to render a few dozen filled rectangles, while Chrome is happily pegged at 60fps (via RequestAnimationFrame).
It's mostly night and day in the opposite direction. Firefox 4+, like IE9+, uses Direct2D on Windows. That leads to canvas being much faster than Chrome (if your graphics card supports that).
On other platforms, results may differ, and it depends on your graphics card. I am guessing that you happen to have a configuration that Chrome runs better on, but most benchmarkers have found (as expected) than Firefox and IE have faster Canvas implementations than Chrome (since they tested on Windows, with cards that can utilize Direct2D).
Canvas on Firefox is hardware accelerated (at least on Windows), so it's really fast. I don't have Chrome installed, but I'm pretty sure it chokes on the FishIETank benchmark with 1000 fish: http://ie.microsoft.com/testdrive/Performance/FishIETank/Def.... Firefox on the other hand easily gets 60 fps with those many fish.
> Canvas on Firefox is hardware accelerated (at least on Windows), so it's really fast.
If your video drivers aren't blacklisted, after I found out by whining about the lack of speed with hwaccel--which wasn't actually active. Check it out at the bottom of the super secret "about:support" URL.
That just means your Firefox isn't benefiting from GPU acceleration. It could either be because your OS or hardware doesn't support it or because your graphics drivers are out of date.
The reason why is unimportant. The end result is the same: terrible performance on Firefox, good performance on Chrome. It's not up to the end user to know or care why.
For the relatively simple canvas rendering I'm doing, I can watch Firefox chugging along at 10fps struggling to render a few dozen filled rectangles, while Chrome is happily pegged at 60fps (via RequestAnimationFrame).
It's just night and day.