Since the announcement last month of AMD's Smart Access Memory, a feature that allows AMD CPUs to access all the VRAM in a Radeon GPU; many were concerned the feature would only work within AMD's ecosystem. Fortunately, this will not be the case. AMD is opening up compatibility to both Intel and Nvidia platforms.
Last week, Nvidia confirmed it's working with Intel to get a feature similar to AMD's Smart Access Memory working on its own graphics cards. Nvidia said the feature is very easy to implement, since it's baked into the PCIe specification. Specifically, the spec is called Resizable BAR Capability.
Since then, AMD stated in an interview with PCWorld that its Radeon group is working with Intel to get this feature supported with RX 6000-series GPUs and Intel's latest CPUs and motherboards. The same goes with AMD's Ryzen group, which is working with Nvidia to get Smart Access Memory working with GeForce GPUs.
For now, we don't know how customized AMD's approach is with its current Ryzen 5000 CPUs, X570 motherboards and RX 6000 GPU pairings. If AMD did a lot of hardware-level optimization, that could give AMD's CPUs , GPUs and relevant motherboards better performance with this feature over Intel and Nvidia's more standardized implementation.
AMD also stated in the PCWorld interview that this feature simply isn't a "toggle switch" you can just turn on. There will be a good chunk of development and optimization required to get good performance gains from the feature. So for now, it looks like AMD is in the lead with Smart Access Memory, as it is already developed and optimized for Ryzen 5000 CPUs and RX 6000 series GPUs. We'll see how long it takes for Intel and Nvidia too long to catch up.