There are some benchmark (1, 2) where Firefox seems slower in Linux than in Windows (and even Firefox Wine is faster), but are those benchmarks really a "normal" user usages?
Firefox has some problems on Linux, but are not all Firefox issues. Some rendering perfomance could change a lot, most it depends which graphic settings you choose.
The "Scroll" Micro-Benchmark
All the tests are done in the same conditions, with the web browser fullscreen at the same resolution 1920x1200 and the font size at 10px.
If you use different window or font size the results will be very different.
The first four browser are on windows xp, then I tested different combinations. The default configuration is:
- fglrx video 3d driver catalyst(win/linux)
- metacity + compositing
- firefox 3.0x no extensions
The other options are:
- rad: the open source radeon driver
- compoff: no compositing
- ezoom: extensions + font size zoom (120%)
- kit: Webkit backend
The first four tests are from Windows.
(less is better, results in milliseconds ms)
In this test it's clear that the video driver used is the most relevant parameter.
Firefox-Wine tests are not present but it is 6000+! In this particular test Firefox Linux is faster than Firefox Windows, even if ctrl+wheel (zoom) is faster on Windows and the fglrx driver is 2X faster than the radeon driver.
The Webkit browsers: Arora, Safari, Midori, Epiphany webkit are not so quick to render the scrolling.
Konqueror doesn't run this test.
Chrome is very fast on Windows and not only in this benchmark, I hope to test the Linux/Gtk version soon.
Swiftfox(3.0.4) speed benefits over Firefox are not visible.
My personal conclusions
If you don't need the Firefox extensions Epiphany gives the best basic browsing experience on Linux, but even Firefox is not so slow. They both share the gecko engine.
Epiphany-WebKit is powerful but not at this micro-benchmark (but relevant in everyday usage).
Opera Linux is not the best browser to scrolling a page, but is the fastest to zoom a page. Unfortunatly I didn't find any micro-benchmark to prove it.
2346 W7 Firefox3.0
W7 Firefox 3.6a1
1935 W7 Safari4
1203 W7 Chrome
1178 OSX Firefox3.0
OSX Firefox 3.6a1
1026 OSX Safari4