If you find the Firestorm seems to freeze up every so often, then try these things, one at a time, testing between each one:
If you have chat saving enabled, and have a large number of chat transcript files, these could be causing the freezes. (Ref. FIRE-11322
.) Try moving your chat transcripts elsewhere and see if the freezing stops.
You can find your chat transcripts by going to Preferences
→ Network & Files -> Directories
→ Conversation logs and transcripts location; click the Open button.
Set Preferences → Network & Cache → Cache Size to maximum (9984MB or the maximum space available, whichever is less)
If you have ever enabled “Full Res Textures”, disable this setting.
→ Rendering → Full Res Textures (dangerous). Ensure that this is NOT checked.
Ctrl-Alt-Q to enable Develop, if it isn't.
Advanced → Debug Settings → Set FastCacheFetchEnabled to FALSE - then relog.
Ctrl-Alt-D to enable Advanced, if it isn't.
Preferences → Graphics → Hardware Settings → Viewer Texture Memory Buffer - reduce by 128. Then relog.
Tip from a user: Windows users: If you're running CrashPlan, open the “Advanced” section of “Backup” settings and uncheck “Back up open files.
For additional suggestions, see the page on Severe Lag.
Mac Os X 10.7 Lion
NVidia systems will freeze shortly after login, possibly followed by a system crash.
This issue is affecting all Viewer 2 based viewers. Please see FIRE-2297 for details.
Please also see the LL JIRAS here SH-2032 & SH-2034
Workaround For Now
Disable Open GL Vertex Buffer objects from the login screen in Preferences → Graphics → Hardware
This will likely badly affect your performance and FPS but for now, at least it should let you login untill this is fixed.
Initial reports suggest that the new generation Macbook Airs running Lion and Intel3000 graphics have the same issue as Nividia Cards.
See this page for documentation on Firestorm 4.6.9 (42969) and earlier.