How to stop Firefox on an SSD from freezing when using the search box or submitting a form?

You might find a benefit from vacuuming the sqlite databases. This command should do it (on Linux):

cd ~/.mozilla/firefox/dasda418.default
for i in *.sqlite
do
echo 'vacuum;' | sqlite3 $i
done

where dasda418.default is your actual Firefox profile directory. Obviously you have to do this when Firefox isn't running. On Windows the command is:

for %i in (*.sqlite) do @echo VACUUM; | sqlite3 %i

This will compact the databases, making them smaller and might solve your problem.

I agree with gorilla about vacuuming the database. A more direct method, independent of OS, is through Firefox's Error Console (Tools menu/Error Console)

In the Code text box paste this (it’s a single line):

Components.classes["@mozilla.org/browser/nav-history-service;1"].getService(Components.interfaces.nsPIPlacesDatabase).DBConnection.executeSimpleSQL("VACUUM");

Press Evaluate. All the UI will freeze for a few seconds while databases are VACUUMed

mozillalinks

Have you tried to disable de disk cache? In Disk properties -> Hardware -> Properties -> Policies : uncheck the Enable write caching on the device You problem reminds me mine, and I think it's related to this box checked. I don't know why I must say as it's supposed to improve performance, even for a SSD disk. But since I've unchecked it, I am not experiencing slow downs in Thunderbird anymore. I wish it will do the same to you.