ASUS releases bios beta version with Resizable BAR function for Z490 motherboards

ASUS has released a bios that adds Resizable BAR support to various motherboards with Intel Z490 chipset. Resizable BAR is also referred to as ‘Smart Access Memory’ by AMD and was initially only supported on AMD motherboards. Intel itself has not yet reported on support for this feature.

ASUS has quietly released bios version 1002, an editor from Tom’s Hardware noted. This bios version was released on Friday and is currently in beta phase. ASUS does not add a changelog to the bios update, but Tom’s Hardware confirms that the update adds support for the Resizable BAR function and Above 4G Decoding, among other things. Before that, the tech site used a Maximus XII Apex, although the update has become available for several ASUS Z490 motherboards, according to Tom’s Hardware. It seems to be mainly about higher positioned motherboards.

The website reports that it is unclear whether Resizable BAR actually works on the motherboard in combination with AMD’s RX 6000 GPUs. It is also possible that this is just preparation for future official support.

AMD already introduced Resizable BAR support with the release of its Radeon RX 6800 graphics cards. The company did this under the name Smart Access Memory, which for the time being only works for Ryzen 5000 CPUs in combination with RX 6000 video cards. The feature allows processors to access the full amount of video memory on a video card, which AMD says can deliver performance gains of up to 11 percent in select games.

However, this function has been included in the PCIe standard for some time, and therefore in theory also works on Intel motherboards, older AMD platforms and Nvidia GPUs. AMD has already stated that it wants to partner with Intel and Nvidia to support this feature on their respective Core CPUs and GeForce GPUs in conjunction with AMD’s products. Nvidia has already confirmed it is working on Resizable BAR support. It is striking, however, that Intel itself has not yet said a word about this function, despite the released bios update from ASUS, which thus adds the function to a motherboard for Intel CPUs.

Support for Resizable BAR on the ASUS ROG Maximus Apex XII. Image via Tom’s Hardware