Firefox Excessive Memory Usage

Jeff Atwood -

I like Firefox. I've even grown to like it slightly more than IE6, mostly because it has a far richer add-on ecosystem.

But I have one serious problem with Firefox:

This screenshot was taken after a few days of regular Firefox usage. That's over 900 megabytes of memory for a single, non-tabbed instance of Firefox.

What's going on? Well, according to my tests, Firefox never seems to release any of the memory it uses-- until you close all instances of Firefox. If you spend enough time browsing the web, and never close Firefox completely, you'll consume nearly a gigabyte of memory!

Because I often keep at least one browser window open for research or reminder purposes, this bites me a lot. I'll look at Task Manager and Firefox will regularly be gobbling up over 400 megabytes. This isn't uncommon. It's normal.

I don't ever recall having this problem with IE 6.

Of course, I can close all instances of Firefox and reduce memory usage back to zero, but why should I have to? I've read this techweb news article on the controversy around Firefox and memory usage, and I've implemented the workaround suggested in that article:

  1. Within Firefox, enter "about:config" (minus the quotation marks) in the address bar
  2. Scroll down to the entry "browser.sessionhistory.max_total_viewers" and double-click it.
  3. In "Enter integer value" field, type..
    • "0" to disable the cache
    • "1" through "8" to set the maximum cache as 1 through 8 previously-viewed pages
    • "-1" to return the cache to its default

Sadly, this fix did very little to address the problem. The above screenshot was taken after setting that value to 1!