Improving Firefox performance on ASUS EeePC 900

I’ve noticed that a bottleneck in Firefox performance on the ASUS EeePC 900 is writing and reading to the disk cache. It is often I wait for something on a page and I notice that the hard disk light is on indicating read/write.

One way of drastically improving the performance is to move the cache to a ramdisk as the built in flash disk in the EeePC is not the quickest one on the block. This way you might also prolong the life of the flash disk as you decrease the number of read/writes to it. The only drawback with this is that you will loose the cache content between reboots, but I don’t think that is a problem. If you have extended your machine’s ram to 2 GB (se another post about that), you have memory to spend for this, but it will probably work on 1 GB machines too.

If you are running EasyPeasy (probably in other distros too) you already have a ramdisk. Check by starting a terminal and enter the df command. If you see "/dev/shm" you have a ramdisk. Otherwise, you first need to create one (Google might be your friend in this case).

1. Start Firefox and in the URL-bar, type about:config and press enter. Click yes on the warning about this being very dangerous.
2. Find the key browser.cache.disk.parent_directory and right click to select Modify. If the key is not present, you right click in the list, select New -> String and type browser.cache.disk.parent_directory
3. As the value for the key, enter /dev/shm
4. Pull down the Edit menu and click on Settings
5. Click on Advanced and select the Network tab
6. Select the Override automatic cache handling and limit the cache size to for example 100 MB (so the cache won’t eat all your ramdisk).
7. Close all Firefox and restart it.

In my case, this drastically improved the Firefox performance.