I am currently on my girlfriends laptop round at her house and I am surfing the net using Firefox 10.0.1. The memory usage is terrible. It may be because of the two McAfee add-ons that she has, I don’t know, but I can see now first hand how some Firefox users are having an amazing experience and others are still lagging behind. The memory usage as opposed to being 200,000-230,000kb as it would be on my laptop with 11 beta 2 is about 350,000kb or more. That said, there is no loss of performance and that is what matters most. I am not looking for answers or solutions, merely saying that the same or very similar software used on one computer can perform completely differently on another and now I appreciate that even more having witnessed it for myself.
I asked him to try turning off the McAfee add-ons, which he kindly did. The result (emphasis again added by me):
I did some very very rudimentary tests earlier at my girlfriends house on her laptop and here is what I found.
With the two McAfee add-ons running everything was fine until I got to about 8 tabs and then the memory began to increase. Then it just climbed up to about 450,000 kb. If I was running the same tab load on my latop, I would expect just over half that amount of memory to be reported in task manager.
I have to say that there was no loss of performance, but the amount of memory being used was very high for the tab load.
The first tab that I had open was google.co.uk. I right clicked on that tab and hit “Close Other Tabs”. The memory stayed at 418,000 kb and that was it. It stayed at that level for about 10 minutes whilst I went and did other stuff. It wasn’t going up or down. 400MB with just Google UK open and nothing else. It’s diabolical.
So I then disabled the 2 McAfee add-ons and every went back to normal. I used a heavy tab load than before. I opened more tabs with more complex content. I must have had about 15 tabs open and the memory use peaked at 386,000 kb.
Then I logged out of Facebook and Hotmail, without closing any tabs, and within 10 seconds the memory had dropped to 330,000 kb.
Then I closed all but 3 tabs and within 30 seconds the memory was about 180,000.
Then I closed all but one tab and the memory settled at just under 100,000 kb. Back to normal. Exactly how I would expect Firefox 10.0.1 to perform.
The extensions in question were McAfee ScriptScan for Firefox 14.4.1 and McAfee Site Advisor 3.4.1
I didn’t have time to test them individually as things got hectic after that, but as you say Nicholas, the seemingly innocent extensions were ruining the memory performance of a perfectly good browser.
I could still load pages etc and navigate around as fast, but the numbers on task manager were sky high.
Firefox has a reputation in particular for not releasing memory when tabs are closed. 75% of installed add-ons are not hosted on AMO, and thus are out of Mozilla’s control. This is killing us. Bug 720856 is my best suggestion for dealing with badly written add-ons such as these ones, but even it feels like weak tea when the problem is so large.