99% of the time, the 630 1gb will be better, especially for gaming. The 610 2gb will be useful doing video or graphical editing where you have a ton of textures and layers and such.
well sir I think that 630 1gb is stronger than 610 even if its 3gb, 4gb or higher. Gt 630 is on the same tier where our gt440 is as i saw it here----->http/www.tomshardware.com/reviews/gaming-graphics-card-review,3107-7.html . I can't really find the 610 if somebody can, you're welcome to prove me wrong