Firefox's performance settings

To give you the fastest and most reliable experience, Firefox automatically uses settings that work best with your computer. You can always change these settings in the General panel of your Firefox Settings page by unchecking the box next to Use recommended performance settings and changing the following:

• Use hardware acceleration when available: This allows Firefox to use your computer's graphics processor, if possible, instead of the main processor, to display graphics-heavy web content such as videos or games. This frees up resources on your computer so it can run other applications, like Firefox, faster. This box is checked by default but the feature isn't available for all graphics processors. You must restart Firefox after changing this setting, before it will take effect.
• Content process limit: With Multiprocess Firefox, also called electrolysis or e10s , Firefox runs web content for all tabs separately from the main Firefox process for increased security and performance. Using multiple content processes can further increase performance and minimize the impact of content process crashes. You can modify this setting if e10s is enabled; however, having too many content processes can slow down your computer, and consequently, Firefox. The recommended maximum is four, but you can set up to seven.