UEFI mode is the preferred option for the Radeon RX 9000 series as AMD updates on how to get the most out of the RDNA 4-based GPUs. UEFI (Unified Extensible Firmware Interface) has been around since 2006 and its first iterations under different names began in the late 1990s as a means to address various needed updates to motherboard BIOS features and support. Windows has supported UEFI since Vistas SP1, so to say the least, it has at least been around for a while now. That being said, owners of motherboards that support UEFI ought to consider enabling it, for optimal performance with AMD Radeon RX 9000 GPUs. Owners of older motherboards that do not support UEFI may want to consider upgrading to a newer model that does.
“To fully leverage the benefits of UEFI, only UEFI Mode will be officially supported starting from the AMD RDNA™ 4 generation of graphics cards (Radeon™ RX 9000 Series Graphics and later).”
-AMD
Aside from the features listed below, one other important feature is the use of Smart Access Memory (aka PCI-Express Resizable BAR or ReBar). Smart access memory enables full access to Radeon graphics memory with select Ryzen CPUs for improved performance. More can be learned about it here, such as when we tested it using Radeon RX 7900 XTX and RX 7900 GPUs, and additional documentation about AMD’s smart technologies is available here.
Per AMD (via support article):
How are UEFI and BIOS different?
Compared to the older “legacy” BIOS firmware, UEFI firmware offers many new and useful features, including:
- Greatly improved security
- Fully specified interfaces that ensure interoperability and testability
- Dependable firmware updates from the internet with minimal user interaction
- Support for hard drives larger than 2.2TB
- Support for many new types of PC hardware, including NVMe SSD boot support
- Windows® Secure Boot for malware prevention
- Faster shutdown, startup, sleep, and resume times
How to enable UEFI in BIOS
AMD has provided BIOS snapshots from ASRock, ASUS, GIGABYTE, and MSI motherboards showing where to find the toggle to enable UEFI or CSM. A step-by-step guide is also included (along with a link to a Microsoft video for verifying OS/hardware support), and can be found here.