@LaloFG: I never said Firefox's CSS support was bad; if you're taking it from the Maze Solver benchmark, it is a known problem: the test hits one specific use case where Firefox will do a LOT of DOM operations and refreshes for nothing - the problem has been detailed, and several fixes are actually ready, but they're all integrated in larger refactorings (especially, how to handle reflow on an absolutely positioned element if it hasn't changed in its dimensions). The day it lands, Firefox will suddenly get comparable results to other browsers, if not go faster.
@przemoli: hardware acceleration is very different on Linux, as all drivers don't support the same acceleration architectures - for example, Firefox 3.6 on Linux, using XRENDER (3.6 wasn't hardware accelerated on Windows) already had results comparable to Direct2D-accelerated IE9 on Windows on Psychedelic Wheel.
However, the new graphics stack used in Firefox since 4.0 doesn't seem to work with XRENDER anymore (at least not on my Radeon 4850 using recent AMD drivers - I should try with recent Free drivers) and Mozilla disabled hardware acceleration on all drivers - right now, WebGL alone is accelerated, and that is only with Nvidia and AMD drivers. When I try to force-enable layers acceleration, Firefox does so many rendering errors it's unusable.
Let's not forget either that there's no version of Safari on Linux, but there ARE several versions of Firefox with wildly varying results:
- the 32-bit official binary from Mozilla, that nobody installs because it's a pain (tarball only)
- 32-bit and 64-bit builds provided by each distribution, which may be outdated as Adam pointed out
- 32-bit and 64-bit builds provided by third parties: the easiest way to install the latest Firefox version on Ubuntu 10.04 LTS (which comes with 3.6 by default) is to use a PPA...
In Chrome's and Opera's cases, it's easier: both binaries are provided by their makers as a .deb or a .rpm package in both 32- and 64-bit flavours, so it is easier to test.
Of course, one solution could be to choose a platform: latest Ubuntu, in 32-bit (netbooks) _and_ 64-bit (desktop systems, recent laptops), with Nvidia graphics, using the latest versions provided for the platform, either by the editor (Chrome, Opera) or the distribution (Firefox).