So what’s bloatware anyway, Part III

Published: May 25th, 2007

Firefox has memory issues. It’s undeniable. Keep Firefox for a few hours with some 15-20 tabs opened at a time, minding you own business and you will get Firefox to grab up to around 150MB. You may notice this or not depending on how much memory you have. 1 GB or better computer users most likely won’t notice it. Drop that to 512 MB and you will start looking for the culprit. Windows task manager will promptly finger Firefox and its sticky little hands covered in memory.

Fast back and forward navigation was added in Firefox 1.5 and it has been pointed as the most memory consuming features with good reason: by design it keeps in memory the last n pages you have visited in a tab so if you need to go back or forward the page will be rendered faster from memory than from the disk cache.

browser.sessionhistory.max_total_viewers is the preference (accessible via about:config) that controls how many pages to store. By default it is set to -1 which means Firefox will decide based on the total amount of memory found in your system. According to the mozillaZine Knowledge Base, these values are 3 for 256 MB systems, 5 for 512MB and 8 for 1Gb and better systems.

To find out, how severe are Firefox 2 memory issues and how much fast page navigation affects I ran a small test:

I created a new profile and set 8 home pages: a Wikipedia article, YouTube, Amazon.com, eBay, Yahoo Games, Netvibes, News.com and Apple.com.
I measured total memory in use after startup.
Then followed these links in each tab:
1. On Wikipedia: clicked on Main Page, then Featured Content.
2. On Netvibes: expanded Featured Feeds, clicked on CNN Money, closed it, then click on the first USA Today news item
3. On Amazon.com: Books, Your Account, See all 41 categories, Software
4. On eBay: eBay express, Computers & Netowkring, IBM/Lenovo, scrolled down and clicked on last item (an x60)
5. On YouTube: Videos, Top Rated (Cat fight Rosie vs Elizabeth), Community
6. On Yahoo games: Video Games, opened halo 2 trailer (a new tab), View Red Carpet and left it running
7. On Apple.com: Store, MacBook from 1099
8. On CNet: Tips and Tricks (top), Home Entertainment (side).
I measured again here.
Then closed four tabs and measured again.

Then I changed browser.sessionhistory.max_total_viewers to 0, cleared the cache and ran the test again. Then I ran the tests against Firefox 1.0.8. These are the results:

Measure	Firefox 2 default	Firefox 2 customized	Firefox 1.0.8
After startup	89,688 KB	90,800 KB	85,600 KB
After navigation	120,660 KB	114,804 KB	107,088 KB
After closing 4 tabs	96,924 KB	80,044 KB	72,808 KB

I get two conclusions from these results:

Firefox 2 uses more memory that 1.0.x
max_total_viewers significantly closes the gap between Firefox 2 and 1.0.x memory usage

Furthermore I can say that turning off fast page navigation affects very little the Firefox experience. When I started writing this series I realized I have turned it off already some time before which explained why I don’t usually have memory issues and I can’t complain about back/forward performance, but it’s indeed faster with the default setting.

From past experience I can say that the difference between Firefox 2 with the custom and the default setting tends to be much bigger than my results suggest on more real situations (more tabs, more back and forth, more open/close tabs). I guess the same could apply for Firefox 1.0.x/2.x comparisons but my test reveals no really dramatic change specially with the custom max_total_viewers.

Previous: Part I: The forgotten ware, Part II: So what’s bloatware anyway

Next: Part IV: Moving forward

This entry was posted on Friday, May 25th, 2007 at 11:38 am and is filed under Articles, Firefox. You can follow any responses to this entry through the RSS 2.0 feed.

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6 Comments on “So what’s bloatware anyway, Part III”

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1. David Naylor
May 25th, 2007 at 4:32 pm
Interesting test. I’ve reduced my number of possible undoable tabs, as well as pages cached. Both set to five.

[Reply]
2. Hi
May 25th, 2007 at 9:02 pm
Wait, when I start-up Firefox, it sits at about 40-50, then rises to about 80. After about an hour of browsing, it’s at 130. And that’s with 40+ extensions.

[Reply]
3. netster007x
May 26th, 2007 at 2:21 pm
But how do those people at Opera make a faster, more feature filled browser that uses less memory? There must be more to it than just extensions. Really, I’m amazed that so many people flock to Firefox rather than Opera. Because of that, Firefox has become a standard browser for sites to base development. I use Firefox for two reasons, add-ons and compatibility. I love IE7’s menu-less UI. It makes browsers with menus look obselete, and allows one-click bookmarking and others, and reduces redundancy, makes controls more logical and fast, and saves screen space. But the browser is short many basics (download manager…) and lacks a user-friendly add-on manager and database. I use the myfirefox theme and personal menu extensions to make Fx2 a near perfect IE7 mimic.

[Reply]
4. Bob
May 28th, 2007 at 8:46 am
I personally hate the menu-less IE7. I have serious issues with the UI and I’m therefore staying away from IE7. I’m not more Firefox than Opera … I am just “anything not IE”. I believe that were it not for both Opera and Firefox, there’d be no IE7 right now, or a planned IE8.

As I’ve said before, I only use two add-ons (IEView and a Canadian dictionary) and after over an hour of my normal usage, I am only sitting at 50MB in use with a peak of 91MB. I’m more than happy with this memory usage.

Having said that, if there’s a better way (i.e. Opera) then perhaps one of the goals of Firefox 4 should be to reduce memory requirements (maybe through efficiencies) to both speed up start-up and overall usage.

[Note: I had written a reply to Percy in his Part II, but it never made it to the site]

[Reply]
5. Percy Cabello
May 28th, 2007 at 9:06 am
Firefox uses at least a layer more of code than Opera or any other application it is made of XUL, JavaScript, XPCOM and an assorted collection of open languages and libraries. This enables its multiplatform capabilities and extensibility at the same time, but at the same time I am sure it accounts for a large part of its memory usage.

Opera on the other hand isn’t designed that way and is not extensible. Anyway, it is a fast application that integrates a lot of nice features only available as extensions for Firefox users. Some users like it that way and some others prefer Firefox. To the present and the foreseeable future (Firefox 3) I like Firefox approach but totally understand other people preferences.

[Reply]
6. Mumblemouth
April 22nd, 2008 at 1:12 pm
I’m probably the last person on the planet who DOESN’T use tabs, just individual open windows for my work. (It just really works better for me). Anyhow, I haven’t experienced any memory issues with FF3v5b. No that said, I also use iFreeMem to clean up stray memory usage overall. (Ooops! I should mention I’m on Mac 10.4.11 PPC) Firefox seems to cruise along very well all day long.

[Reply]