I wouldn't bother about the memory that much.
Because even old cards can have 64MB+
The problems is that they have significantly lower bandwidth (connection system ram - VRAM) and fillrate, which can cause serious slowdowns when you do an "action game" with BM ... I would for example assume that grid wars runs far worse on a stone age 64MB card (GF2 GTS) than on a GF FX5200 with 32MB of VRAM like the ones used in the old iBook
Because even old cards can have 64MB+
The problems is that they have significantly lower bandwidth (connection system ram - VRAM) and fillrate, which can cause serious slowdowns when you do an "action game" with BM ... I would for example assume that grid wars runs far worse on a stone age 64MB card (GF2 GTS) than on a GF FX5200 with 32MB of VRAM like the ones used in the old iBook