for the graphics on OpenGL, onboard ram will only count if the GFX card is onboard (it then shares Ram with system rather than having dedicated ram) ... if the card is seperate, system ram is irrelevant.

 

now,a 650 has more than enough grunt. I'd check you've got drivers from Nivida themselves - NOT microsoft or the card makers - and what else you have running. this is a system / software / configuration problem, not hardware.