AMD just announced its Radeon RX 6000 series graphics cards, including the 6900 XT, 6800 XT, and the 6800. One of the core features of the new cards is AMD Smart Memory Access (SAM) which improves gaming performance by up to 11%. But how does Smart Memory Access work?
When you’re using an all-AMD system with a Ryzen 5000 CPU and a Radeon RX 6000 graphics card, the CPU has direct access to the GPU’s memory sub-system via the PCIe 4.0 lanes.
Update: AMD’s Frank Azor believes that SAM isn’t based on DirectStorage. The exact functioning is still not clear but it appears that this is a proprietary solution similar to AMD SmartShift on Renoir notebooks, which allows the 500 series chipsets to bring the GPU and CPU closer to each other, thereby reducing overhead and latency.
Generally, the memory is first transferred from the storage drive to the main memory (RAM) on the motherboard and from there to the dedicated VRAM of the GPU. It’s unclear how exactly Smart Access Memory works, does it bypass the main memory or is it somehow tied to DX12’s DirectStorage which uses the GPU for memory compression/decompression and bypasses the CPU/main memory as well. We’ve already asked AMD about the same and will update as we get an answer.