Asbis Africa has introduced the Inno3D GeForce GTX 550 Ti with 1Gb and 2Gb.

Today's games demand a lot of memory to use a large number of bump and transparent textures to describe faces of characters and render realistic gaming scenes, so these games put higher demands on the capacities of graphics memory.
DX11 and Win7 are becoming more compute-intensive, whether it be for AA, Tessellation or for things like CUDA/PhysX and DirectCompute. There also have programmes such as Adobe and AutoDesk that tie-in to GPGPU.