MapD predates good virtual (unified) memory support on GPUs and so we built our own caching mechanism where each GPU has its own buffer pool and pulls from a CP

MapD predates good virtual (unified) memory support on GPUs and so we built our own caching mechanism where each GPU has its own buffer pool and pulls from a CPU buffer pool (i.e a network of buffer pools). This approach still has the advantage of giving us a lot of control of where we put data, how much we leave for other processes, as well as allowing us to pin data in VRAM on a specific GPU.