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Firefox 1.5 Stability Problems? Readers And Mozilla Respond
Firefox users wrote to us detailing their problems with the browser, and we asked Mozilla for some answers.
December 21, 2005
21 Min Read
On December 8, 2005, we published a story that wondered: Firefox 1.5: Not Ready For Prime Time? In response, some 450 (and climbing) InternetWeek, InformationWeek, TechWeb Pipelines, and Scot's Newsletter readers have sent details about their experiences with Firefox 1.5. A picture is emerging about Firefox 1.5 in the real world -- on a small percentage of Windows, Mac, and Linux computers -- that is less than positive.
Before we get too far down that path, however, let's put things in perspective. More than 60 percent of the people who responded to our request for personal experiences with Firefox 1.5 reported they had no problems whatsoever with the browser software. And there is absolutely no statistically valid way to draw any hard conclusions about how many people are having stability issues with Firefox 1.5 based on this small sample size. At a rough guess, the number of people experiencing serious problems is probably well under 10 percent of all the people who have downloaded and installed Firefox 1.5.
Nevertheless, the people who are experiencing problems aren't having fun. And a lot of our readers are reporting the same woes:
Firefox's use of physical and virtual memory is exceptionally high.
CPU usage spikes to 100 percent (usually while loading a Web page).
The browser freezes up for seconds, minutes, or permanently.
The browser won't launch until they remove an errant "firefox.exe" process in Task Manager.
The browser crashes suddenly (usually while loading a Web page).
The browser has trouble loading specific pages, but there's no commonality among users as to which pages won't load.
The initial launch of Firefox loads slower.
Third-party application hyperlinks (such as a link in an e-mail message) take a long time to open a new Firefox tab or to launch the browser.
Memory spikes like these caused us to look more closely into Firefox's use of virtual and physical memory. (Click to enlarge image.) |
Some Examples From Readers
Here's what some of our readers wrote about their problems with Firefox 1.5:I have to agree with everything you said about Firefox 1.5 in your latest newsletter, as I am having the exact same problems you described:
The browser frequently freezes for a few minutes, most often when opening a link from another program. It also spikes in CPU usage during these freezes.
Several sites always cause Firefox to just hang, needing to be killed in Task Manager. I've had to stop visiting a couple of these sites, it was so frequent.
The rendering seems to have gotten a little worse, not better, in version 1.5.
PDFs have never been that reliable in Firefox, even with the latest version of Adobe Reader, but at least in 1.0.x they worked most of the time. I find it rarely works in the newest version.
All of this is on a completely clean profile as well on a clean install, so it cannot be blamed on a faulty upgrade or extensions.
All in all, I'm giving out your advice to people that they hold off until a future revision, such as 1.5.0.1, fixes these issues.Thanks for your story. Before I read it I had only seen good reviews and wondered if it was just me experiencing all of these issues. -- Shane McAliece
I'm having problems with Web pages loading incompletely and improperly. It's a crapshoot as to when I'll experience these problems. Sometimes the pages load fine, other times not. What's troubling is that sometimes it looks like I'm losing my Internet connection when the pages won't load at all (and I get the Firefox equivalent of a 404 message). When that happens, I can't even retrieve my e-mail --Outlook times out. Then a minute later, everything will be fine. -- Betty Nakamoto
Firefox 1.5 has caused me to use IE6 for many more Web sites. With Firefox, many pages just don't open and I don't have the time to figure out why. Some pages are extremely slow to load. --Ted Gates
I'm getting 'Page not found' or 'Site not available' [sic] messages at least 15-20 times more frequently than ever before -- which is especially vexing since I am often simply going from page to page on the exact same site at the time! -- Scott Thompson
The Motley Fool, where I use it the most. Some links don't show; text is not formatted properly (runs off the screen). Once IE comes out with tabbed browsing I may drop it. -- Paul KnudsenInterestingly, the page-compatibility issues aren't consistent. Of the many Web pages that readers reported having problems displaying in Firefox 1.5, we haven't been able to reproduce a single one. They all work for us. At the same time, we have also had trouble with specific pages that won't load properly or at all. The problem may have nothing at all to do with Web-page rendering, and more to do with some intermittent overall aspect of program reliability, such as caching issues.
Memory, CPU, And Stability Woes
More comments from readers:
Memory usage has shot way up! On my machine, Firefox 1.0.7 used to use about 100MB -- now Firefox 1.5 shows 250MB or more [based on Windows Task Manager's Processes tab]. -- Richard Frisch
I have three major issues with this release. 1) I am among those that have seen Firefox grow to over 350,000k in memory. 2) I have seen it consume up to 40 percent of my CPU for extended amounts of time for seemingly no reason, even while idling. My PC is a two-month old Dell 600xps/dual processor, so this program is eating up serious CPU cycles. 3) This morning Firefox kept crashing and would not stay up for more than 15 minutes at a time. -- Kevin Mahanay
I have encountered the 100 percent CPU freeze-up problem. And it comes close to making the OS useless. Some Web pages fail every time I try to load them. -- Rob DuWors
I have experienced Firefox 1.5 using up to 1GB of memory on an Athlon X2 3800 with 2GB of RAM. I’ve had to end the firefox.exe process multiple times and have had to reboot XP to get things running smoothly a few times. I didn't seem to have these problems on earlier beta versions of the product. -- Jared Pickerell
Before reading your article, I thought I was the only one experiencing crashes and lock-ups with Firefox 1.5. Also, I was on a conference call the other day, not doing anything on my XP-Home machine, but with several Firefox windows open, and after an hour or so I had a crash warning from both Firefox and Windows. That seems to be explainable by the memory leak you described. Also, the past versions of Firefox always grabbed 100 percent of CPU and froze my machine when I would hit the "Go" button (so I had to be careful and avoid it), and I was hoping 1.5 would have fixed this, to no avail. But it's still better than IE. -- Rob Gaddis
NY Times online. -- Ralph Adams
I find that 1.5 is slow to load (longer than 20 seconds) on the initial start after Windows reboot. After that, it loads more quickly, and more as it did every time with the 1.0.x releases. -- PJ Lacroix
Initial opening of Web pages is much slower and page-to-page transitions get slower the longer the session goes. -- Scott Thompson
That's a small sample of the 450 messages we've received to date. Roughly speaking, every fourth or fifth message that rolls in offers a report like these. We continue to be interested in your insights about Firefox 1.5, and Mozilla is interested in receiving these reports. If you'd like to contribute, send us an e-mail with details about your Firefox 1.5 experience. (The subject line should read "Firefox15_Experiences." If the phrase doesn't appear in your e-mail subject field automatically, please type it in manually.)One of the fallacies about software bugs is that, for a problem to be real, everyone has to have it. That's just not the case. In fact, it is far more common for a widely distributed application like Firefox to have a long list of problems that only a small percentage of users have. We don't know the exact percentages for each problem we've listed, but if multiple people in a selection of 450 have the same problem, it is most likely a real issue.
Mozilla's Response
We spoke with Mozilla's Mike Schroepfer, Vice President, Engineering and Chris Beard, Vice President, Products. Although both Mozilla executives were attentive and interested in our findings, they did not appear to be fazed by the problems we reported to them. "We have more than 10 million downloads of Firefox 1.5, and the overwhelming feedback we've received from people downloading has been positive," said Schroepfer. "We have heard some reports [of high memory use], and we're working through them now in hopes of a successful resolution. It's our goal to make Firefox users happy."
The next release of Firefox, version 1.5.0.1, is expected in late January or early February. Schroepfer said the two main goals of that release are security and stability.
"We have heard some reports [of high memory use], and we're working through them now in hopes of a successful resolution. It's our goal to make Firefox users happy." |
However, Schroepfer and Beard admitted that Mozilla is not working on any of the problems in our bulleted list except for the high memory usage issue. So problems like high CPU usage, program freezes and lock-ups, and long pauses before a tab or the browser opens from hyperlink clicks in other applications might not be fixed in the next version of the program.
Let Mozilla Know
One possible reason why Mozilla might not be seeing many reports on the program-freezing issue is that Firefox's built-in crash-reporting functionality (the Talkback 1.5 extension) doesn't report it. Talkback is only tripped by an actual Firefox crash, and in most cases the freezing issue rights itself after a few minutes.
Firefox users who want to help improve their browser of choice should avail themselves of the avenues of communication Mozilla provides. In addition to sending a message to the authors of this story, you can visit the Mozilla Firefox message board. If your system crashes and Talkback opens on your computer, allow it to send a report to Mozilla. If you encounter a Web site that doesn't load properly in Firefox, open the browser's Help menu and choose the Report a Broken Web Site option. More experienced readers can use Mozilla's Bugzilla bug-reporting tool, to provide detailed information to Firefox's developers about any problems you experience.
Other helpful links for Firefox users include these FAQs:
Frequently Asked Support Questions
Can Bfcache Be The Problem?
The high memory usage problem, many of our reader e-mails point out, was also evident in previous versions of Firefox. But some people report that it's worse in this version, with Firefox displacing as much as 250MB to 500MB of physical and virtual memory on a Windows PC with 1GB of RAM. Of all the problems on our list, this is the most commonly reported. It's unclear whether it is linked to high CPU usage and program freezing, but it's at least conceivable that it might be.This is purely speculation, but it's also possible that Firefox 1.5's new Back and Forward button caching functionality — which speeds up the display of recently viewed Web pages when you click those buttons — is actually an abetting factor to the memory woes. Schroepfer mentioned that there's a new small module in Firefox known as bfcache which supports that performance improvement.Looking at the details about how much data bfcache stores, however, it doesn't seem like that would be enough to cause the problems. The browser.sessionhistory.max_total_viewers setting in Firefox's about:config settings area, which is similar to the Windows Registry, stores only five pages on machines with 512MB of RAM, for example.
If your Firefox installation is generating high memory numbers (you can check it by pressing Ctrl-Alt-Del, going to your Windows Task Manager, clicking on your Processes tab, and checking the "Mem. Usage" and "VM Size" numbers on the firefox.exe line), there's another settings change that might help. Access about:config by typing that exact phrase in the browser Address bar and pressing Enter. In about:config, look for this setting:
browser.cache.memory.enable
Check to make sure its "Value" setting reads "true." Then follow these steps:
1. Right-click anywhere on the about:config window area and choose New and Integer from the pop-up menu.2. The New Integer Value box will open. Copy this setting name and paste it into the open dialog box:
browser.cache.memory.capacity
3. The Enter Integer Value box will open. The default setting is -1, and it should preserve Firefox's existing mode of operation.
4. Consult this page for more information about what specific setting to add. For RAM sizes between 512BM and 1GB, start with 15000. For RAM sizes between 128MB and 512M, try 5000. Note: If you have less than 128MB of RAM, that's probably the cause of your Firefox issues.
If this tip works for you, or doesn't, or you have a better one, drop us an e-mail about it.
Pushing The Memory Envelope
This story is not about causes -- it's about symptoms. In our earlier story we speculated that altered JavaScript support and a possible application memory leak could be causing some of the problems. However, we can't definitively point to changes in JavaScript support or memory leaks as the cause of the problems some people are having with Firefox 1.5, and after reading 450 e-mails, both of those possible causes seem less likely to us.Many of those who reported they aren't having trouble also wondered whether the people who are experiencing difficulty didn't properly uninstall previous versions (especially beta versions) of Firefox before they installed Firefox 1.5. A related point is whether people reporting issues might not have poorly written Firefox extensions installed, or Firefox extensions that might have been improperly tested for Firefox 1.5. These are legitimate questions -- although, based on statements people have made in their e-mails, many are having trouble with cleanly installed versions of Firefox 1.5 that had no extensions or themes installed.
What is patently clear is that a substantial number of Firefox users have personally experienced Firefox's penchant for using copious amounts of memory. We decided to push a typical Firefox configuration by visiting some typical (but not excessively) graphics-rich Web sites, to see how that would affect memory usage. The goal was to reproduce the memory-management problems seen previously.
Less Tabs, Same Memory
We ran Firefox 1.5 in Windows XP in a consistent pattern over the course of a couple of hours. We opened new pages in tabs until five to seven tabs were open, closed all but two of the tabs, and then waited a few minutes to repeat the process.We opened a total of about 80 pages in tabs this way. At all times, one tab was a Weather Underground page opened to the San Francisco weather radar, which is a looping series of six optimized JPEGs. The other tabs were opened to pages on the site with an archive of nature and weather photos. These photos are nothing special; they're all JPEGs and none was more than 20KB. In fact, most of the photos were less than 15KB.
Instead of using a sterile, Safe-Mode Firefox 1.5 for this test, we decided to use a "real world" setup. As a result, Adblock and Flashblock were installed, JavaScript was turned on, and Java was turned off. So while there were two very common extensions in use here, there was no Flash and no Java.
The red and green lines show physical RAM accessible to Firefox. The jumps match newly opened tabs, and the level areas match closed tabs. No memory was returned. (Click for complete image.)
The screen shot above shows a custom Performance Monitor setup, which graphs several key memory statistics for firefox.exe. The most interesting elements are the red lines, which show physical RAM accessible to Firefox, and the green lines, which show physical RAM accessible only to Firefox.
The two lines move up in steps; the jumps match the points when we opened series of new tabs, and the level areas match times when we closed the tabs and then waited before opening a new set. Notice that, although we repeatedly closed back to two open tabs and minimized Firefox to the taskbar, Firefox almost never gave back a single MB of memory after the first 30 minutes or so.
Whose Fault?
Did Firefox do this? Did one of the two extensions play a part? Could it be the Flash or Java plug-in (the former blocked, the latter disabled) making a monkey out of Mozilla?It really doesn't matter, because they aren't the ones whose names appeared in the Task Manager next to some ungodly amount of RAM. Even if something else is feasting on all that system memory, it's Mozilla that gets stuck with the tab.
So, Firefox has problems with Windows -- that much is clear. How does it fare on Linux and Mac OS systems?
We worked with version 1.5 on both Linux (using Xandros and the latest Ubuntu distro) and a current version of Mac OS X, in addition to Windows 2000 and Windows XP SP2 installs. In both cases, as far as we're concerned, the jury is still out: Although we can't send either the Linux or Mac OS versions of Firefox 1.5 to the doghouse without better evidence, we're also not willing to let either of them off the hook just yet.
Part of the conflict is a matter of numbers: Of the reader e-mails we received on this subject, ten were from desktop Linux users. Of those, only one person noted definite signs of a memory-management problem on a Linux-based Firefox 1.5 install.
Memory leaks: Yes, [they] have been there since 1.0.6, that I've noticed. Didn't see problems in Linux with older versions (1.0.6 on KDE 3.4). A way to suck memory quickly: Do some eBay searches. All those little thumbnails chow memory like Liz Taylor at a chocolate convention. --John Palmer
Sorry, Liz.
The same quandary, by the way, applies to Firefox on OS X: Of the e-mail we received from Mac users, we saw only a few complaints, including one that reported freezes and the need to force the Firefox program to quit, and two that reported identical problems using scrollbars in Firefox 1.5 (a bug we can't duplicate). Once again, it's a case where maybe Firefox on OS X isn't oinking its way through acres of RAM the way it so often does on Windows -- or maybe enough people just haven't complained loudly enough yet.Recommendations
Nothing has changed about the recommendations we made in the last story. If Firefox is an everyday professional tool for you -- as it is for both of us -- you might want to hang back on installing Firefox 1.5, at least until Firefox 1.5.0.1 is released. In our experience, Firefox 1.0.7 is far more stable. If you don't use the browser very often, odds are that you won't have problems, so version 1.5 is a better bet in that scenario.
We also recommend backing up your Firefox user profile before installing Firefox 1.5. Some people are reporting an issue with corrupted user profiles when they try to uninstall Firefox. If you plan to install Firefox 1.5, your first step should be to remove any and all previous Firefox installations using Add or Remove Programs in the Control Panel. (Doing this leaves behind all your customizations, bookmarks, cookies, extensions, and themes, which will be picked up by version 1.5 when you install it.)
You might also consider wiping your Firefox plug-ins, extensions, and themes prior to uninstalling your previous version of Firefox. It adds more work, but it's less likely that you'll encounter the problems that some people have had if you upgrade that way.
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