Complex sentence: In modern 3D graphics cards, the video memory may also hold 3D vector data, textures, backbuffers, overlays and GPU programs, and sometimes takes the form of a Shared Memory Architecture (SMA).
Split into simpler sentences: In modern 3D graphics cards, there may also be memory (possibly of another sort) dedicated to hold 3D vector data, textures, backbuffers, overlays and GPU programs. Sometimes this takes the form of a Shared Memory Architecture (SMA).