A lot has been said about Firefox and its memory usage. Some report no problems with Firefox, and that it behaves well and doesn’t hog their system. Others bring tales of woe about how Firefox has brought their system to its knees by hogging all the available memory and CPU.
My systems fall in to the former category. Firefox, on my system, seems to work pretty well, and this is using the default memory management settings. It almost never needs more than 80 MB of memory and makes comparatively conservative use of virtual memory too. CPU can be a bit high while big pages are loading, but otherwise it’s pretty well-behaved. It even uses less memory than IE7 Beta 2 (which Fred Langa claims should be the opposite).
But I’ve also seen some systems where Firefox’s memory usage grows and grows, and after a couple of hours it has hogged 300 MB of memory and is using some or all of the CPU, even when idle. This is still prevalent, even on Firefox 1.5. Scot Finnie goes over some of this in a Computerworld article.
Mozilla are aware of the issues and have been working to try and cure any memory leaks that may be occurring – several patches have been checked in as a result and these should hopefully make it into Firefox 2.0 or 3.0. But Firefox’s memory problem is a difficult one to tackle, because the browser is so customisable. Every copy of Firefox is used in a different way, so in tracking down memory leaks it’s fair to say that Mozilla have their work cut out.
Firefox’s ability to be expanded using extensions also creates another variable – some extensions will also put more strain on memory. There are also those which are quite CPU intensive.
And everybody’s computer is different – from the hardware to the operating system to the programs it runs. Some computers, like my laptop, run Firefox fine. Others may have major problems, simply because of how they’ve been set up. And remember that in Windows Firefox has two distinct disadvantages against Internet Explorer – it’s not built into the operating system like IE is and is designed to be easily portable to other platforms, which usually makes the code less efficient.
So to say that Firefox is a memory hog isn’t entirely fair. Sure, for some it is one, but for others it’s not.