Mozilla: Firefox 3 Beta Beats Apple's Safari, Microsoft IE 7 in Memory Test

The cat's out of the bag, and Mike Shaver, director of ecosystem development at Mozilla, now puts it this way: "I'm going to share some non-news with you: Firefox has memory leaks."

But results of closed-door comparisons pitting the upcoming Firefox 3 Beta against Microsoft Internet Explorer 7 and Apple's Safari browser show better results than rivals but that more work needs to be done, Mozilla developers say.

In the comparison, Mozilla developers had all three browsers start with blank pages, then open a URL that caused "many windows" to open, shut them all down and then re-opened a blank page for all. The result: IE 7 ended up showing 118 MB of memory use, Safari with 110 MB and Firefox 3, code-named "Minefield," used 94 MB.

The tests, though, are likely to generate some criticism or shoulder shrugs. Mike Schroepfer, Mozilla's vice president of engineering, says, "These tests. . . clearly do not reproduce the conditions causing people to have much larger memory use. Obviously missing is user interaction, XMLHttpRequest, and other interactive elements. This is also a clean profile with no extensions."

Whether the results win believers or not, Mozilla is clearly working on the memory issue. Shroepfer writes, "If we tried to construct a more 'real-world' user-event driving test what do people think is both representative and useful? E.g. logging into gmail, search for a message, log into flickr, do stuff, etc... Even spot testing by hand key builds of FF might give us a useful measuring stick."

The "do stuff" part might actually lead to a comparison that gets a little more mileage in the marketplace. (Note: In a separate "quick and dirty" test, he said, Firefox 2.0.0.7 consumed less memory than IE 7 and Safari when "logging into gmail, google reader, and loading cnn.com on a 2GIG Vista system.")

Testing aside, Shaver writes that Firefox users can look for improvements. "The real punch line of this for Firefox users is that Firefox 3 will continue to improve memory usage over long-term usage, and you'll soon be able to try it out for yourself with the upcoming Firefox 3 Beta."