Flash Game Performance: Browser Comparison

Its getting crunch time for The Basement's first Flash game. We are under an non-disclosure, so my hands are tied as far as releasing details about the who, what, when, where, why, and how. (Although you can check out some of the character art at Amy Kingman's blog).

With the deadline quickly approaching, I am spending a majority of my time squashing bugs and trying to squeeze out a few more frames per second out of the game. One thing I noticed while testing was the vast differences in performance between browsers.

I am running XP and am comparing Chrome, IE 6, and Firefox 2. I am using two different builds of the game: an older one from Friday vs the latest build that has gone through a few optimizations. I made sure that I had no other programs running and only opened 1 tab in 1 browser at a time to ensure there was no noise or discrepancies.

Firefox 2:
Friday Build - 22 FPS
Latest Build - 25 FPS

IE 6:
Friday Build - 29 FPS
Latest Build - 32 FPS!

Chrome:
Friday Build - 24 FPS
Latest Build - 29 FPS

I got to admit I'm all about Firefox... but its hard to argue against these numbers. I haven't taken the plunge into Firefox 3 yet, mainly due to the lack of Flash Tracer support, but once I do I will update this with my findings (also will have to jump into IE 7 as well to make it fair... altho IE seems to be doing fine without updates).

It is also interesting to note that both IE and Firefox increased by 3 Frames Per Second while Chrome jumped 5. Not sure why... which isn't helpful. I can tell you that most of the improvements involved creating smaller bitmap areas to be drawn, using object pools, cutting back the items in the pool, and removing clips from the stage when they were not being used. Not sure why Chrome would handle these improvements differently, I guess I need a better understanding of the bottlenecks of each browser.

If anyone has any insights on the matter, I would love to hear them.

Update:
After being reassured by the comments below that Flash Tracer did actually exist for FF3, I went ahead and downloaded it as well as IE 7. Here is what I found:

IE 7:
Friday Build - 29 FPS
Latest Build - 32 FPS

Firefox 3:
Friday Build - 28 FPS
Latest Build - 34 FPS

IE 7 didn't seem to add any performance boost to the game, but IE 6 was already so fast that it did not matter. Firefox 3, on the other hand, gained six fps on the old build and a whopping nine on the Latest build! The swf was published at 35 fps, so the 34fps from Firefox 3 is incredible.