Firefox usually freezes for about a second whenever I search for something from the toolbar search box, when submitting a form, or when clearing the search box history. I suspect it has something to do with the auto-complete feature. Using Windows 7's Resource Monitor, the problem seems to be from the file:

C:\Users\<username>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile>\formhistory.sqlite-journal

I believe this is a temporary file which caches database writes. The following screenshot shows the very high response times from six different searches, and that the queue length on drive C shoots off the scale:

My Firefox profile is on an Intel X25-M G2 SSD. The problem doesn't seem to occur if I create a new profile on a hard disk drive. However, I'd like to know why the problem exists on the SSD in the first place (because it's an annoying problem which contradicts the reason I bought an SSD, and it might happen with other applications too), and how to prevent it. It still occurs if Firefox is started in safe mode, and with the recent beta versions.

Updates:

• VACUUMing the Firefox profile databases does not help with this problem.
• The SSD Optimizer in the Intel SSD Toolbox does not help either.