Scrolling a page with SVG elements is very slow. Testcase from @chriscoyier: http://codepen.io/adrianosmond/pen/LCogn This testcase is interesting to investigate the reason of the slowdown because it compares scrolling of a page with SVG images against the same one but with PNG images only.
Confirmed with nightly 24.0a1 (June 24) running on Ubuntu 12.04. Also, chrome exhibits the same behavior.
The codepen.io page is quite difficult to debug. I created a smaller testcase at: philbit.com/sprites2.html
I have added Philip Roger's testcase as bug's main URL reference. The SVG-only container is almost impossible to scroll on my system whereas PNG version scrolls smoothly.
I'd expect that this is something Seth's recent work on SVG images would fix/improve. CC'ing Seth for his thoughts.
just noticed a fix for this issue has landed in chromium: https://code.google.com/p/chromium/issues/detail?id=253091
I tested Philip's testcase on my local build with the in-progress fix for bug 764299, and performance is much better. I've added that bug as a blocker.
another test (using CSS animations) just to confirm that performance on 29.0a2 is way better than it used to be a few months ago - SVG as img[src]: http://jsbin.com/bixun/1 and SVG as background-image: http://jsbin.com/bixun/3