there is a mention of machine specs that FF uses to test filters somewhere here in the forums. it sets the standard for rejecting filters that take too long to render. so, i'd guess that would be your base or reference machine. it was something like a 1 ghz cpu with 1 gig of ram or something like that and i believe the rejection time was anything over 15 minutes to render. i have no idea where that thread is now, but you could try some of those specs as search criteria and maybe find it.
If wishes were horses... there'd be a whole lot of horse crap to clean up!
Craig