Fix a memory leak in Firefox 1.0
Firefox is supposed to dynamically release memory from its RAM cache to other Windows applications as needed. Unfortunately, Firefox 1.0 seems to consume more memory than it should, which hurts performance, when set to the default of 51200 KB (51 MB).
To solve this, Firefox power users recommend limiting the memory cache using the Configuration Console. This frees up memory for other apps, speeding up everything to a greater or a lesser extent, depending on your machine and the applications you run. Here's how the trick works:
Step 1. Type about
:config into Firefox's Address Bar and press Enter.
Step 2. Right-click any row, then click New, Integer. Type or paste the following preference name into the dialog box that appears (this is a hidden preference that doesn't exist in the Configuration Console until you create it):
browser.cache.memory.capacity
Step 3. Click OK, then enter the following integer number into the next dialog box, representing 16 MB of RAM for the cache:
16000
Step 4. Click OK to close the dialog box, then close all instances of Firefox and restart it.
For a lengthy discussion of this option, see Mozillazine's forum topic 172041.
http://windowssecrets.com/041202/#top1