I'm running Firefox v9.0.1 under Win7 Home Premium 64 bit, with a dual core Intel T4400 (Core 2) CPU running at 2.2GHz, with 3GB of RAM.
This is a new (mis)behavior for F… (read more)
I'm running Firefox v9.0.1 under Win7 Home Premium 64 bit, with a dual core Intel T4400 (Core 2) CPU running at 2.2GHz, with 3GB of RAM.
This is a new (mis)behavior for FireFox.
Problem appears as periodic, temporary freezing of the FireFox UI.
During these times (lasting up to 30 seconds), FireFox will not display new content, will not respond to mouseclicks, will not render typed text. These freezes can affect performance systemwide, degrading the performance of other applications, even with Firefox minimized.
Originally, I thought it was due to the MS Outlook webmail application...but it isn't. The same problem occurs in Firefox sessions that have never loaded an Outlook webmail page.
I composited some screenshots of CPU usage and posted the result here. I'd post a PDF if I knew a site that would permit (more or less) anonymous posters to upload one.
That page is composed from images taken from Mark Russinovich's Process Explorer utility to show system resource usage. There is no I/O usage that corresponds to the CPU use.
Firefox is definitely the offending application.
Every 60 seconds, Firefox usage spikes in one CPU core, to over 90%. Sometimes Firefox usage manages to spill into the second core as well (I don't know how it manages to do that).
ProcesExplorer's per-thread info (bottom of the image) demonstrates that this excessive CPU usage isn't happening in a plugin. It's coming form Firefox, proper.
As you can see in the ProcessExplorer treeview, I'm running the PortableApps installation of FireFox. But I don't think that affects the excessive CPU usage. After all, it never used to do this. And now, after the upgrade to v9.0.1, it does.
Also, a standard install of Firefox on this same computer (v8.0.1) does NOT exhibit the excessive-CPU use behavior.
I'd appreciate any help you can offer to get Firefox's CPU usage to calm back down again. I several users who have gone over to Chrome because of this bug.