Tuesday, March 4th 2025
AMD Radeon RX 9000 Series Works Best with UEFI-Only Systems
AMD has announced that beginning with its RDNA 4 architecture, only Unified Extensible Firmware Interface (UEFI) Mode will be officially supported for the Radeon RX 9000 Series graphics cards and later models. This decision is intended to harness the full capabilities of the advanced UEFI, ensuring improved performance, enhanced security, and a smoother user experience. UEFI, a modern replacement for the traditional BIOS, functions as a compact operating system residing on the motherboard. It plays a vital role in initializing processors, configuring memory, and managing essential hardware components. Its features include faster boot times, support for storage devices larger than 2.2 TB, and robust protection mechanisms such as Windows Secure Boot. These capabilities represent a significant leap forward compared to legacy BIOS systems.
To accommodate modern hardware innovations like AMD's next-generation graphics, motherboards typically offer UEFI Mode and Compatibility Support Module (CSM) Mode. CSM emulates older BIOS functions but restricts access to many of UEFI's advanced features, such as AMD Smart Access Memory. By mandating UEFI Mode, AMD ensures that users of its latest graphics cards enjoy optimal compatibility, performance, and security benefits. This requirement is a natural evolution in PC technology, encouraging users to upgrade their system configurations to meet modern standards. As consumers prepare for the next wave of AMD GPUs, verifying that both hardware and operating systems are properly set up for UEFI Mode is a necessary step to fully leverage the advantages offered by the RDNA 4 graphics cards.
Sources:
AMD, via VideoCardz
To accommodate modern hardware innovations like AMD's next-generation graphics, motherboards typically offer UEFI Mode and Compatibility Support Module (CSM) Mode. CSM emulates older BIOS functions but restricts access to many of UEFI's advanced features, such as AMD Smart Access Memory. By mandating UEFI Mode, AMD ensures that users of its latest graphics cards enjoy optimal compatibility, performance, and security benefits. This requirement is a natural evolution in PC technology, encouraging users to upgrade their system configurations to meet modern standards. As consumers prepare for the next wave of AMD GPUs, verifying that both hardware and operating systems are properly set up for UEFI Mode is a necessary step to fully leverage the advantages offered by the RDNA 4 graphics cards.
23 Comments on AMD Radeon RX 9000 Series Works Best with UEFI-Only Systems
I found out when I tried to boot a GTX580 in a B550 system.
I ran into this issue on my Z690/12600k when I used windows Media creation tool, some how I ended up with MBR with Windows 10. I only noticed weeks after, so when I moved to win11 I used rufus to make sure GPT was enabled.
I guess the question is will it boot and run with legacy mode enabled, IMO it still should run and just have some kind of pop-up window when drivers are installed telling users to switch to non CSM mode and features they will get.
UEFI has been mainstream for twenty-one f*cking years. CSM is about as welcome as a sinus infection at this point and it would be a whole lot better if the standard was just dropped entirely.
The OS' view of hardware depends on what the BIOS/UEFI presents, mostly in the form of ACPI tables. It's not like the OS can force-enable ReBAR without the UEFI parts being present first.
As for exact performance numbers it's hard to tell, but Intel Arc is crippled on systems without ReBAR for example. Maybe AMD modified their architecture enough to warrant the same requirement, but don't want to face the support costs of lower performance BIOS/CSM systems. Without a technical explanation from them we can only speculate.
No person in their right mind would use CSM/BIOS on a spanking new Ryzen 9XXX/Intel Core Ultra 2XX with Radeon RX9070 GPU.
My last 3 motherboards all died, but the respective Radeon HD7700 / GTX960 / GTX1080 still work fine so if I ever need BIOS compatible GPU there are plenty around. Also have a small form factor GT720 2GB lying around just in case.
Edit: ok I glanced over your 4000 an up mention.my bad.
There were people pairing 4090 with 4790k cpu's....