What Smart Access Memory Means for 500-Series Motherboard Owners
The feature behind this announcement is AMD's Smart Access Memory (SAM), the company's branded implementation of a PCI Express capability usually called Resizable BAR. Traditionally, a computer's processor could only see a small window of a graphics card's video memory at one time, often 256 MB, and had to move that window around to reach the rest. Resizable BAR lets the CPU address the full pool of graphics memory directly, which can reduce overhead when large amounts of game data such as textures and geometry are being transferred.
MSI, like other major board makers, brought support to its AMD 500-series lineup, which covers the X570, B550 and A520 chipsets, through BIOS updates. That matters because the capability depends on firmware as much as hardware. Owners do not need a new board, but they do need to update and configure it.
What you generally need
- A compatible AMD Ryzen processor. Support was aimed mainly at Ryzen 5000 series chips, with some later additions for other models, so check MSI's support page for your exact board.
- A graphics card that supports Resizable BAR.
- A current BIOS for your motherboard, installed carefully according to MSI's instructions.
- Windows installed in UEFI mode, with Compatibility Support Module (CSM) disabled.
- The relevant BIOS options enabled, usually labelled "Above 4G Decoding" and "Re-Size BAR Support".
Realistic expectations
Performance gains vary by game and resolution. Some titles show a modest improvement in frame rates, many show little difference, and a few may run slightly worse. It is a worthwhile setting to test rather than a guaranteed upgrade, so compare results in the games you actually play.
A BIOS update always carries a small risk, so do not interrupt power during flashing, and note your existing settings first. For other explainers from this journal, browse the Journal or the Guides section.