Firefox 3 Trounces IE, Opera and Safari in Memory Tests

Since it entered the beta testing phase late last year, Firefox 3 has seen a steady reduction in the amount of memory the browser consumes on the desktop. Now only weeks from a final release, Mozilla’s Firefox 3 has been shown to use significantly less memory than Internet Explorer 7 or Opera — long the browser to beat when it comes to memory use.

Almost a year ago, we wrote a piece for Wired.com calling Firefox 2 a memory hog and questioning the browser’s future in light of its bloat. But the good news for Firefox fans is that those days will soon be a thing of the past.

According to recent performance tests, Firefox 3 uses 60 percent less memory than the current Firefox 2 on Windows. That’s good news for Mozilla, which is hoping to take the mobile world by storm later this year.

Couple the improved memory use with some coming improvements in the way Firefox 3 handles multiple page requests and you’ve got a recipe for what could be a fastest browser around.

And Mozilla isn’t the only source for impressive Firefox 3 memory tests. Ars Technica recently pitted the latest Firefox 3 beta 4 (see our review) against IE 7, Safari 3.0.4 beta and Opera 9.5 beta and found that Firefox 3 came out on top, using just 200 MB of RAM. The other browsers ranged from nearly IE 7’s whopping 500 MB to Opera 9.5 beta which was Firefox’s closest competitor, using 250 MB of RAM.

Both sets of tests involved fairly typical browsing sessions — opening multiple tabs, cycling windows and closing tabs and windows. Of course outside factors like add-ons and extensions will affect performance somewhat, but Mozilla has reached out to add-on developers in an effort to reduce memory usage there as well.

I’ve been running Firefox 3 beta 4 as my main browser in Mac OS X since it was released. My experience has been that Firefox very rarely reaches 200MB of RAM. My current setup includes the AdBlock Plus add-on, Firebug, Better Gmail, Better Google Reader, StumbleUpon, DownThemAll, Weave, Prism, Google Notebook, Total Validator and Greasemonkey, though Greasemonkey is currently disabled since it doesn’t support beta 4 yet.

The same set of extensions running in Firefox 2 uses around 500MB on average and sometimes, after having 30+ tabs open for the better part of day, that number climbs to the 1 GB mark. It’s worth noting that Activity Monitor in OS X can be slightly misleading, but the inaccuracy would be reflected in both cases.

That Firefox 3 uses less than half the memory of its predecessor shouldn’t be a surprise since reducing the memory footprint has been one of Mozilla’s main goals from the beginning.

Thanks For the original post in http://blog.wired.com