@sittingbear - Thanks, but I've been doing that ever since FF version 2 or somewhere back there, prior to that in Netscape, and just about every other browser I've used. Would hate to think how much in resources it would try to use if I didn't have things limited there.

But it's not really caching that's causing the current apparent app bloat for me, it's the newer versions' tendency to split its processes up into several pieces and use predictive technology or something to pre-load tabs and javascript. Or at least that's what it looks like it's doing. I've gotten some relief by switching off that feature in About:Config (then a new version comes along and I have to find the new config setting for it, but so what else is new) and usually given my particular browsing habits the RAM usage now mostly hovers around 500-700 MB. It will still run away with things much more than that at times, which is really annoying if I have the game running alongside of it. For everyday browsing where I'm not using up much RAM at the time already, it doesn't matter as much.

Definitely try the rate limit. Since your normal save is only at 50-80 fps you may not have fried it but it's still being over taxed unnecessarly and it's age might be a factor.

As for Firefox, it's becoming more of a mess with each release. I had to disable the process forking on my laptop because it was running away with memory way too much and dragging it to the ground. The swapping was generating extra heat. Doing so makes it run like it did prior. I've noticed no difference in the memory leak management using the forking on my desktop and still have to restart regularly. In fact it makes it worse as you've seen.

Mozilla's argument would be that they don't have this process forking thing worked out quite right for all user circumstances yet (then it should have stayed in beta testing where it belonged). And users on their forums will complain bitterly about every trivial little thing, though this one is much more intrusive and I'm glad to hear I'm not the only user with reasonable expectations having trouble with it.

Sorry to hijack, this thread isn't about Firefox, but it seemed relevant as we were talking about everyday applications like web browsers running off with all of a system's resources because no one in the world would be using their computer for something else other than what that app/browser was designed for. Chrome was always the biggest culprit here, even when the browser wasn't running and the user had no Chrome sessions even open. The others seem to be catching up quickly.

Back to the topic at hand though, hope the OP has gotten their fps under control by now.