I finally solved my FF3 problems!

I was excited when I heard that FF3 resolved the memory leak problems in FF2 so I downloaded it on the official Download Day (June 18) in eager anticipation. Unfortunately even though most people reported better performance, that honestly was not my experience. If anything, FF3 seemed to run at 100% CPU usage even more frequently for me than FF2 did. I got in the habit of keeping Windows Task Manager open at all times so I could keep an eye it - FF3 never ran at less than 60%. Every time it remained in the 90+% range I would close down FF and restart it, and within minutes it would ramp right back up to the top range.

Even more concerning was that it had my hard drive constantly running, literally. Since my primary hard drive is about reaching what I consider to be the end of its reliable life span (yes, I have multiple backups!), I was really worried that this was going to accelerate failure.

I hadn't been able to find any successful solutions and was really getting aggravated over possibly having to scrap my favorite browser. The clincher was yesterday; all of sudden my hard drive starting spinning out of control. It sounded like a jet engine, getting faster and faster and louder and louder until I was literally afraid it was going to blow up or burst into flames. My computer wouldn't shut down and I had to hit the kill switch on my wall to shut off the power running to the machine. And of course this all resulted in a BSOD, my first ever in 20+ years of using desktop computers.

This morning I was determined to either fix it or kill FF3. I hate IE, and I've just started playing with Chrome now that they've change the EULA, but FF has a lot of add-ons, especially for website development, that I've come to depend on and use every day.

I just spent all morning searching the tech forums, this time focusing solely on the hard drive problems rather than the more widely reported memory leakage problems, and finally can report that I have FF3 running between 3-15% CPU usage and my hard drive is finally getting a much needed break.

So if you've been experiencing similar problems, hit the jump and I'll share the steps I took to get it performing correctly on my machine.


I'll share everything I did, one by one, but I need to note that it was the final step that resolved the issue. I did each of these one at a time and restarted FF3 to check the results. I don't yet know if the effect was cumulative, or if the final step alone was the answer. When I have a little more time I am going to try turning the anti-phishing and malicious site filters back on and see if the problem returns and report back on that. If I understand correctly, I need to have them running for a few days before I'll see if the problem returns.

1. There have been several reports of problems caused by Firefox's anti-phishing and malicious site filters, and many people have reported successful results just by turning these options off (Tools>Options>Security). Note that you will have to pay careful attention to the websites you visit when you have these options turned off. If you frequently surf unknown or sketchy websites, you'll need to be especially careful.

2. Next I tried a Linux fix that some people reported had worked for them in the WinXP environment. That involved changing the default value of the parameter urlclassifier.updatecachemax from -1 to 104857600 (which is one megabyte). You can do this by typing about:config in your url-bar (assure Firefox that you won't do anything crazy) and type urlclassifier in the filter box. urlclassifier.updatecachemax should be the last entry you see; double-click in the value field and change it. Restart Firefox and verify that the change was made.

3. The next recommend fix I tried was to change the default for browser.cache.memory to "false". You access this parameter the same as above by typing about: config in your URL-bar, then using the filter field to sort. Clicking on the value for browser.cache.memory will change it from "true" to "false". Again, restart Firefox and verify that the change was made.

4. The final step was to delete the file urlclassifier2.sqlite, which was from my Firefox2 profile. Make sure Firefox is closed first, then run a search for the file on your hard drive, it will most likely be in your C:\Documents and Settings\your name here\Local Settings\Application Data\Mozilla\Firefox\Profiles.
I deleted that file, restarted Firefox and voila, my hard drive was at peace and Firefox's CPU usage was at 10%. It's been running for a few hours now with six windows and ten tabs open and it has been performing like a champ. I also took a look at urlclassifier3.sqlite from my FF3 profile, but since the size was right where it should be at about 52mb I decided to leave it alone. Some earlier builds had a problem with it growing to tremendous size, so if yours is larger than this you might want to delete it and let it rebuild after making sure you are running the most current release.

Now I've got to mention that I am geek only up to a point and some of the stuff on those tech forums goes right over my head. What I gather is there have been problems with the anti-phishing/malicious site filters and the way the list of harmful sites are downloaded to the urlclassifier file and then compared against the sites you visit. If anyone can provide additional clarification or point out any mistakes I may have made in my explanations, your input is more than welcome.

If you have been experiencing the same frustrating problems I have had with Firefox3, I hope this provides you with some much needed peace.

Now if we can only resolve the Flash problems!