I had the same experience with past versions of Firefox, but Firefox 4 is finally equivalent to Chrome on my machine, and in graphics-heavy cases, it's faster with both 2D (XRender) and 3D (WebGL) (in many cases, anyway).
What operating system are you on and what build of Firefox 4 are you running? I am using the nightlies on Arch Linux x64 with kernel 2.6.36.
OSX, following the betas. WebGL is a very different, very new environment, though. Its speed depends on a lot aside from the JS engine.
edit:
Most of my testing involves jQuery DOM manipulation, and benchmarking some DOM-free, stratght JS utility code / mini-libraries I've written, and one moderately-large one in the works. Because that's what I'm writing. Real benchmarks trump more scientifical benchmarks, for my purposes. YMMV, absolutely, these are just my outcomes.
For a specific case, changing a callback-based array iteration to a for loop, totalled after 10,000 empty operations (making it do something and accounting for that code showed almost no difference):
Chrome 9: <1ms difference
5ms average after change
On FF4b7: 15ms difference
15ms average after change (note that this means it was ~30ms before, a full 6x slower than Chrome)
On FF3: 40ms difference
51ms average after change
I'd be interested in two things (well, quite a few, but these two especially): any change in FF4b8, and a link to your code or (better) a bug report on the performance issue; we'll get to it after FF4 if it's not already better.
Comments
I had the same experience with past versions of Firefox, but Firefox 4 is finally equivalent to Chrome on my machine, and in graphics-heavy cases, it's faster with both 2D (XRender) and 3D (WebGL) (in many cases, anyway).
What operating system are you on and what build of Firefox 4 are you running? I am using the nightlies on Arch Linux x64 with kernel 2.6.36.
OSX, following the betas. WebGL is a very different, very new environment, though. Its speed depends on a lot aside from the JS engine.
edit:
Most of my testing involves jQuery DOM manipulation, and benchmarking some DOM-free, stratght JS utility code / mini-libraries I've written, and one moderately-large one in the works. Because that's what I'm writing. Real benchmarks trump more scientifical benchmarks, for my purposes. YMMV, absolutely, these are just my outcomes.
For a specific case, changing a callback-based array iteration to a for loop, totalled after 10,000 empty operations (making it do something and accounting for that code showed almost no difference):
I'd be interested in two things (well, quite a few, but these two especially): any change in FF4b8, and a link to your code or (better) a bug report on the performance issue; we'll get to it after FF4 if it's not already better.