I would say that is not maxing out your 64MB card cause I run it at 1280x1024 at 32bit color with all options and stuff turned on and it is very comfy on my athlonxp 1600+ and geforce2gts 32 meg card.
Just kind of curious, I was planning to get a 4GB GTX 680, to load up Skyrim texture mods, as my 1.5GB GTX 580 doesn't cut it. So I got to wondering if there was any limitation regarding video memory ...