Asus implements Resizable BAR (aka AMD SAM) support on Intel Z490, H470 and B460 motherboards
AMD’s Smart Access Memory might appear as a novel feature that takes advantage of the new RX 6000 GPUs when coupled with the Ryzen 5000 desktop CPUs, but this technology (also known as Resizable Base Address Register) has been available hidden within the PCIe 3.x specifications for more than 4 years now. This means that Intel and even Nvidia can take advantage of it, as well, and it looks like some Intel motherboards are already getting support for the feature. Nvidia RTX 3000 owners unfortunately still need to wait until early 2021.
As noted by Twitter user KOMACHI_ENSAKA and later on reported by Tom’s Hardware, Asus introduced a new Z490 BIOS (version 1002) that now supports the Resizable BAR feature. German Asus representative Chris Wafers confirmed this in a more recent tweet, and further added that the new BIOS is now rolling out for H470 and B460 motherboards. However, this is still a beta release that may contain bugs, so users are advised to try it at their own risk.
Chris Wafers also included a slide with the estimated performance gains that the Resizable BAR feature brings to Intel mobo owners. We have seen from initial tests that AMD’s SAM may have little to no impact on some games, but there are a few games that can benefit from it, like Forza Horizon 4. This game was used by Asus to showcase the performance increase on a configuration that includes the ROG Maximus XII Hero (WiFi) mobo running an Intel Core i7-10700K coupled with an RX 6800XT card. There is no mention of the exact graphics settings used for the test, but we see a performance increase of 13.37%, which translates to ~20 fps. AMD also showed that the SAM feature can boost performance by 13% in 4K, so Intel’s performance gains seem to be in line here. It remains to be seen if Nvidia’s implementation can outperform AMD’s.