I’ve just killed and restarted Firefox, then duped my current set of tabs over to Chrome (in-house jukebox using websockets, a slideshare presentation, couple of open Google Docs spreadsheets, a Pivotal tracker session, a couple of tabs of a local development project, Google Plus, and this HN thread). Totalling up ‘Real mem’ in Activity Monitor shows Chrome 18 using 735.4mb (of which 33mb is Flash). Firefox 13 (beta release to be fair) is coming in at 450mb (of which 65mb is Flash).
The internal memory measurements (about:memory) come out as 835mb resident for Chrome, and 324mb (of ‘explicit’, whatever that is) for Firefox.
I’m not using any extensions in Chrome. In Firefox I’ve got installed Firebug, FireFontFamily, FireQuery, Lastpass, PDF.js and QuickJava.
Edit: oops, missed cloning a tab with a video in over to Chrome. That explains the disparity in Flash, and you could probably expect to increase Chrome’s real mem usage a little had I not closed it already…
This bug fix won't make much of a change right after starting Firefox, it just prevents memory from building up over time due to closed tabs. Additionally it's effective in nightly builds not beta, so 15.0a1 not 13.
Your comparison is useful overall, but not relevant to this change.
With Firebug installed, you most likely have JIT disabled http://antennasoft.net/robcee/2009/12/15/firebug-and-the-jit.... I would suggest you use a separate 'webdev' profile for such things (the inbuilt web console that is now in firefox is also getting there).
That was true in 2009 but was fixed in January 2010: https://bugzilla.mozilla.org/show_bug.cgi?id=534120#c52 (although it’s true that if you’re actively debugging scripts the JIT turns off - Firebug has the script panel off by default)
Incredible, I've been doing all my browsing for the past year with the script and console panels activated and had no idea that it was disabling the JIT for every page that I visited. Just turned them off, and I can't believe how accustomed I'd become to sluggish webpages. Thanks for the link!
The internal memory measurements (about:memory) come out as 835mb resident for Chrome, and 324mb (of ‘explicit’, whatever that is) for Firefox.
I’m not using any extensions in Chrome. In Firefox I’ve got installed Firebug, FireFontFamily, FireQuery, Lastpass, PDF.js and QuickJava.
Edit: oops, missed cloning a tab with a video in over to Chrome. That explains the disparity in Flash, and you could probably expect to increase Chrome’s real mem usage a little had I not closed it already…