AMD Smart Access Memory (SAM / Resizable BAR)

AMD Smart Access Memory is AMD's consumer branding for the PCI-SIG Resizable BAR (Base Address Register) specification. Traditional PCIe limits CPU access to the GPU's frame buffer to a 256 MB aperture window. Resizable BAR / SAM expands this to the full GPU VRAM (e.g., 16–24 GB on flagship GPUs), eliminating bottlenecks where the CPU must re-map textures and assets in multiple 256 MB chunks. Performance improvements of 5–15% are observed in CPU-limited GPU workloads and open-world games. Requires a compatible CPU (Ryzen 5000+/Core 11th gen+), GPU (RX 6000+/RTX 30+), and motherboard BIOS support.