My read of the patent is that it discusses a virtual memory system that allows the GPU to page memory into cache according to various scopes, (based on tile or

My read of the patent is that it discusses a virtual memory system that allows the GPU to page memory into cache according to various scopes, (based on tile or threadgroup or maybe even shader stage?). But aren't caches already a dynamic copy of main memory? Don't GPUs already prefetch buffers as needed? What is actually new here?