https://wccftech.com/amd-smart-access-memory-enabled-on-intel-z490-motherboard-noticeable-performance-gains-with-radeon-rx-6800-xt/

Several motherboard makers have started adding support for AMD's Smart Access Memory tech on Radeon RX 6800 XT & RX 6800 graphics cards to the Intel-based 400-series motherboards. ASUS and MSI are the first to allow support for SAM with ASRock and Gigabyte quickly working on getting their own support out too. Japanese outlet, ASCII, has posted the first benchmarks of how well the feature performs on the Intel platform, showing a noticeable performance improvement.

AMD's Smart Access Memory technology which is a fancy name for BAR (Base Address Register)  will not require users to invest in a PCIe Gen 4 platform as it will be supported by PCIe Gen 3 too. Based on what we know so far, BAR essentially defines how much discrete GPU memory space can be mapped and today's PCs are typically limited to 256 MB of mapped memory. AMD claims that with SAM (Smart Access Memory), they can access all of the GPU memory, removing bottlenecks to allow for faster performance.