Disable Precaching in Firefox
Don't allow Firefox to eat up your systems memory by disabling precaching. To do this,
- Open up Firefox and in the address bar type about:config and press Enter.
- Scroll & find the line that says browser.sessionhistory.max_total_viewers.
- Double click on that line and change the value from -1 to 0 and click Ok.
- Restart Firefox. Precaching will be disabled.