Sam's World Of No

To me, Firefox is a pretty near perfect piece of software; in fact I only have 2 major gripes with it. Firstly, you can only ever open one session at a time. Sure you can open multiple instances, multiple tabs, whatever, but these instances will always share cookies, sessions and ghost stories. There’s no way, yet, of sorting this out, which makes development a pain. Want to be logged into the same website as two different users? Time to boot up Internet Explorer.

Gripe number 2 is Firefox’s memory usage. Firefox looks at your system’s memory like Ronnie Biggs looks at a bag of money, and after only a couple of hours, it’s not uncommon to find that everyone’s favourite browser is using over a 100 meg of memory. If you leave your pc on overnight, as I did last night to get some downloads finished, and happen to leave Firefox open, doing nothing, expect to find it using up to 300 meg in the morning. Frankly, it sucks, and I seem to spend my life opening and closing browser windows just to keep them functional.

To put this problem in context, I feel it should be pointed out that internet browsers are usually the most demanding software packages running on my PC. Google Desktop is mostly tame and under control nowadays. Explorer (as in the Windows kernel) uses less than half your average, brand new, browser instance. MSN Messenger uses only just less memory than the kernel (bloatware tastic), and as I ran the tests below, I had Excel open to collate the results. Even this hefty program was using less than my web browsers, by some margin. I say this to emphasise that my system is hardly under stress; yet still rendering web pages with Firefox seems to be problem.

I’m not convinced that upgrading to version 2.0.0.9 has helped matters either; memory usage now seems worse than ever. This morning I decided to run some tests, side by side with Internet Explorer 7 (version 7.0.5730.11), over what I considered to be a fair sample of sites. I visit them all regularly and have chosen them because of their different technologies and function. For each test, new instances of IE and FF were opened, the relevant page was accessed (including any logins) and then the counter was started. I recorded the memory usage (in KB) every 2 minutes for 10 minutes for both browsers. Here are the results:

BBC News

BBC News is my homepage, and was 10 years old this week. It features biased and smug news reporting, a penchant for spelling, grammatical and factual errors (especially at the weekend) and some really quite terrible JavaScript red box things in the middle. Once it is loaded (88 requests later), it makes no further http requests. This doesn’t stop Firefox from continuing to eat up memory, however:

Minutes	0	2	4	6	8	10
Firefox:	47,136	47,732	50,744	51,088	52,236	52,232
Internet Explorer:	44,092	43,992	43,996	43,976	43,976	43,976

Ouch. As you can see, Firefox’s memory usage over the course of the test increases by 5096KB. Internet Explorer, on the other hand, has a pretty stable consumption, and actually decreases over the time period. Bear in mind that once this page is loaded, there is nothing else to do. Exactly what does Firefox need another 5 meg of memory for, then?

Facebook Homepage

Weighing in at 105 requests for the initial load, the internal Facebook homepage (the one where you see people you barely know leaving 10 groups at at time and adverts for Experian’s credit reporting), is a beast - especially when you remember that it is little more than text that is displayed. No matter for Firefox, though - it will use memory whatever the situation:

Minutes	0	2	4	6	8	10
Firefox:	58,256	61,554	61,620	61,554	61,558	61,776
Internet Explorer:	60,524	60,300	60,292	60,276	60,276	60,252

Again, IE is stable. FF is poor. What’s more, during this test FF was also constantly using between 1 and 6% CPU - presumably because of the flash-based advert served on the left hand side. IE rendered a similar advert but used 0% CPU.

Gmail

I fully expected Gmail to really humiliate Firefox. It does almost 2 requests a minute; meaning that at minute zero it had completed 65 requests, and by minute 10 that number was 82. After examining the size of these requests, however, I could see that the files returned were often around the 26b mark. This is of course the server checking for new mail and sending back a ‘no new mail’ message (well, an empty JSON array or something similar). 2 requests a minute, for ten minutes, that return tiny files? That’s nothing that Firefox can’t handle, providing you can grease its palm with another 5 mb of memory:

Minutes	0	2	4	6	8	10
Firefox:	62,708	64,764	64,972	65,040	66,096	67,128
Internet Explorer:	61,372	61,400	61,416	61,352	61,588	61,628

It’s almost as if it doesn’t matter what website you look at; Firefox always wants more. IE is fine, and will sit there for days without bringing your system to a halt.

Martiny

I decided to take a different tack, and to try a much simpler site. Martiny is the homepage of Kristen Mason, someone I used to occasionally email and chat with on forums. Her site is sparse and, well, pretty random to someone who doesn’t know about, well, whatever it is she is talking about. With only one request to load the page, and with no images, CSS, JavaScript, our browsers had a pretty easy time of it:

Minutes	0	2	4	6	8	10
Firefox:	47,548	47,644	47,588	47,592	47,740	47,728
Internet Explorer:	42,528	42,336	42,336	42,796	42,796	42,796

Apparently both FF and IE needed an extra 200kb of memory to continue rendering this page for 10 minutes. Perhaps they were being cocky and booted up solitaire in the background for a quick game, thus using the remaining memory. Who knows.

Sam’s World Of No

It seemed only fair to test my own site as well. I’m a simple guy, I like simple pleasures and 20 requests is enough for my site to display a blog, some images I hacked together in not very many minutes, and to integrate with a couple of external services. Still, Firefox demands 400k to keep the lights on for 10 minutes.

Minutes	0	2	4	6	8	10
Firefox:	48,348	48,804	48,820	48,816	48,784	48,784
Internet Explorer:	44,004	43,728	43,728	43,704	43,704	43,656

Sucks to be me.

I am not saying that IE is better than FF. Patently, it isn’t. Even without firebug, which is the Firefox killer app, Mozilla’s browser is nicer, more user-friendly and generally easier to use than IE. I am prepared to give Firefox more memory as it is better and does more. What annoys me is the increasing memory usage, which isn’t immediately explainable. I’m not a win32 programmer, but if IE doesn’t need more memory, why does Firefox?

The only conclusions I can draw is that, for some reason, Firefox is using up memory. Over the next few days I will be attempting various suggested remedies (including disabling the Google Firefox Toolbar, ironically enough) and I’ll try to keep you posted. If anybody has any suggestions, please let me know.

(Writing this post took 30 minutes or so. Firefox is now using 117,060k of memory and about 5% CPU. Almost constantly. Ouch.)

(I’ve now proofed for 5 minutes. Firefox is now up to 134,024k.)