AMD has announced that its upcoming RX 9070 series (RDNA 4) GPUs will require a UEFI system for optimal compatibility. Put simply, it has dropped support for the older BIOS and CSM standards, requiring users to make the necessary shift to UEFI. While this doesn't mean RDNA 4 GPUs will cease to function with legacy firmware, AMD offers no assurance.
Colloquial use has employed BIOS as a blanket term for all sorts of motherboard firmwares, including UEFI. BIOS stands for Basic Input/Output System and contains essential instructions that allow your PC to initialize hardware, perform the Power-On-Self-Test and load the Operating System from storage. As the years followed, BIOS was superseded by UEFI which offers a GUI, Secure Boot and can support drives larger than 2.2TB. Notably, UEFI retains the core functionality of BIOS, just sprinkled with a pinch of modern features.
UEFI offers a feature dubbed CSM (Compatibility Support Module) that allows it to emulate a BIOS environment to maintain compatibility with older hardware. Lucky for us, modern CPUs (post Intel's Nehalem architecture) and motherboards are designed with UEFI support in mind. In most cases, the limiting factor is how your drive is partitioned; if it's using the MBR scheme, you'll need to convert it to GPT, necessary for UEFI.
In a new resource article, AMD has outlined the advantages UEFI has over legacy firmware. AMD's RDNA 4 GPUs will exclusively support UEFI systems, as it has dropped support for older CSM/Legacy Modes. So if you were planning to grab an RX 9070-series GPU this week, best make sure your system is running UEFI.
Let's make one thing clear, this does not mean that RDNA 4 (and future) GPUs will not boot on older systems. AMD simply does not guarantee an optimal experience, stating that your GPU could be missing out on necessary features such as Smart Access Memory. It doesn't make sense to invest in a $600 GPU if you're not going to realize its true potential. Plus, you might just get hit with unexplained BSODs and other compatibility problems.
The article contains further details on how you can smoothly transition between BIOS and UEFI. We'll go over the steps briefly: Ensure your storage device is partitioned using the GPT scheme. Afterward, enter the UEFI menu at startup. Navigate to the "Boot" menu then locate and disable the "CSM" or "Compatibility Support Module" option. Since most systems are UEFI-compatible, AMD is just stating the obvious to make sure every user has a streamlined and consistent experience.
