Firefox 41 Will Use 5x Less Memory (In Certain Cases)

Release date: September 22, 2015.

If you have installed and enabled the Adblock Plus extension on Firefox, then we have some great news: the upcoming Firefox 41 release will use less memory than ever before.

As it turns out, just by enabling Adblock Plus, users see an additional 60-70 MB increase to the memory usage. In addition to that, it adds an additional 4 megabytes per iframe, which means that in very rare cases (such as loading Techruch and rolling over all their social buttons for every story), Firefox memory usage becomes pretty insane:

Firefox (default): 194 MB
Firefox with AdBlock Plus: 417 MB

If you want to go even more extreme, by loading a page with over 400 iframes (yes, they do exist), the difference is even crazier:

Firefox (default): 370 MB
Firefox with AdBlock Plus: 1960 MB

Well, thanks to Cameron McCormack, the bug that was reported more than 14 years ago has finally been fixed! The result? Around 3.6 MB decrease in memory usage per iframe, so If you were to load the 400 iframe page with Firefox 41, the memory efficency is much better:

Firefox 41 with AdBlock Plus: 450 MB

That’s a pretty amazing (and amazingly slow) fix.

[Via: Mozilla]