From my investigation, it's slow because hardware acceleration is disable. See image below, about
:support page in both platform, Ubuntu and Windows.
On Windows - hardware acceleration enable.
On Ubuntu - hardware acceleration disable.
The problem is, there is no way to enable hardware acceleration in Ubuntu's Firefox. My card is ATI/AMD Radeon HD5650, I installed my driver right with CCC usable(the one in Additional Drivers from Ubuntu.), force enable hardware acceleration won't work.
I heard it also effects NVIDIA user with driver in Additional Drivers and upgrade the driver to latest version didn't fix a thing.
I read some test and found out that Linux and slow browser is nothing to surprise about.
Hardware Acceleration Performance Benchmarks.
However, you can test it yourself with HTML5 Fish Bowl
. I tested it myself, and found that on Windows, Firefox gave the best result even surpasses IE9, on Ubuntu it merely survive crash.
I'm using Firefox 13 on Ubuntu 12.04 LTS, updated every thing to date, there's nothing change. Is there a way to fix this? Thanks.