Ah. So the threshold is higher with the newer ones. Makes sense if they require 3 or 4 gigs just to launch.
Still, having a halfway decent graphics card is always nice. I'd go for at least 2 gigs of graphics RAM, more if you like HD resource packs. I've never really used resource or texture packs, and my card, which has 2 gigs of graphics RAM, still manages to get the job done. I have 8 gigs of normal RAM, not that impressive nowadays but it still works.
Still, having a halfway decent graphics card is always nice. I'd go for at least 2 gigs of graphics RAM, more if you like HD resource packs. I've never really used resource or texture packs, and my card, which has 2 gigs of graphics RAM, still manages to get the job done. I have 8 gigs of normal RAM, not that impressive nowadays but it still works.