Speed up Firefox
Speed Up Firefox by Restrict Use of High RAM.
Follow the steps:
1. Run Firefox, type "about: config" in the address bar and press Enter.
2. Then you will get the following screen, click on the "I'll be
careful, I promise" to continue.
3. 'Right-click' anywhere on the page and select 'New >Boolean'.
4. In the dialog box, type "config.trim_on_minimize" preferred name, and then click 'OK'.
5. Finally, set the value to "True" and 'restart' Firefox.