https://wccftech.com/amd-brings-smart-access-memory-resizable-bar-to-ryzen-3000-desktop-cpus/

In addition to the Radeon RX 6700 XT unveil, AMD also announced that is bringing Smart Access Memory (Resizable Bar) technology to its Ryzen 3000 Desktop CPUs based on Zen 2 cores. This is great news for a large majority of PC users who are running Matisse CPUs and the extra boost in performance thanks to BAR support is much welcomed by the gaming community.

AMD Smart Access Memory or Resizable BAR technology is great when it works and we have seen now in multiple performance tests that the gains are there. It's definitely not across the board but in certain titles, you can get a big boost in performance for free. For Ryzen 3000, AMD has stated that users can expect a performance boost of up to 16% which is pretty impressive. AMD showed the performance improvement with its own Radeon RX 6000 series class GPUs but we know that motherboard manufacturers have opened BAR support for NVIDIA GPUs on AMD motherboards too.