NVIDIA has confirmed to GamersNexus that it is already working on its own version of direct CPU access to video memory, similar to AMD’s SAM (Smart Access Memory).
From NVIDIA, re:SAM: “The capability for resizable BAR is part of the PCI Express spec. NVIDIA hardware supports this functionality and will enable it on Ampere GPUs through future software updates. We have it working internally and are seeing similar performance results.”
— GamersNexus (@GamersNexus) November 12, 2020
Nvidia graphics cards support the (resizable BAR) functionality and it will be available on Ampere graphics cards with a future driver update. We are already conducting internal tests of the technology and are seeing similar performance gains
AMD introduced SAM (Smart Access Memory) at the presentation of the Radeon RX 6000 series graphics cards. The technology provides tight integration of AMD graphics cards and processors, allowing Ryzen 5000 to get direct access to the video memory of Radeon RX 6000 cards. The technology works only with new graphics cards and processors coming out in November 2020 and later.
According to information from AMD, this technology allows you to get a performance increase of 5-10%.
NVIDIA’s version will be more versatile – the company announced that it will work with both Intel and AMD processors, and will give about the same performance gain. There is not even a limitation on the connection bandwidth – Intel 10th Gen desktop processors still do not support PCIe 4.0.
The SAM counterpart will be available to NVIDIA GeForce RTX users with one of the future free driver updates.
The exact timing of the update has not been announced, but most likely it will not be released until the end of 2020.