That last link looks about the same to me in Chrome dev and Firefox nightly, for...

mstange · on Sept 6, 2016

It's 5-10 fps in Firefox Nightly for me, and 50-60 fps in Chrome Canary, on OS X.

bzbarsky · on Sept 6, 2016

OK. They're both about 20fps or so for me (at least eyeballing it).

Mind filing the bug, since you can reproduce and profile?

Edit: mstange did in fact file one: https://bugzilla.mozilla.org/show_bug.cgi?id=1300848

effie · on Sept 6, 2016

How do you measure fps? Is there an add-on for that?

robin_reala · on Sept 6, 2016

In Firefox go to about:config and flip layers.acceleration.draw-fps to true. In Chrome I think it’s either in dev tools settings or in chrome://flags

scrollaway · on Sept 6, 2016

Dragging the scrubber around updates at the same speed, really? I'm not on Nightly, maybe that's the difference, but if that's the case that's great news.