AMD RDNA3 ISA Reference Guide Published

Following last month's launch of the Radeon RX 7900 series graphics cards, AMD's GPUOpen group has now published the instruction set architecture (ISA) programming guide for those interested in RDNA3 GPUs.

The new GPUOpen reference guide covers the instruction set architecture for the new AMD RDNA3 graphics processors. This is intended for developers wanting to do very low-level optimizations around RDNA3 shader code or carrying out similar work around AMD's AMDGPU LLVM shader compiler back-end or similar compiler-level tuning/enhancements. The guide covers the RDNA3 shader code execution model, wave execution models, shader core interactions with the memory hierarchy, available instructions, and other details.

The 606 page PDF only covers the shader ISA and doesn't cover programming details for other IP blocks. While years ago AMD focused on providing publicly available programming documentation for their hardware as part of their open-source driver effort, that hasn't been the case in a number of generations. In modern times, AMD focuses on providing their open-source Linux graphics driver stack as a sort of living documentation paired with their documented register header files for each GPU. They've focused their efforts on improving their Linux driver and keeping that in excellent shape as opposed to working on the resources vetting their documentation and all of the internal and legal challenges involved in clearing documentation for public consumption. It was a big effort with little return on investment that it was determined to be better spent enhancing the open-source driver itself.

The AMD Radeon RX 7900 series has been running great if using Linux 6.0+ and ideally Mesa 22.3/23.0-devel Git for the latest RADV and RadeonSI drivers. Learn more from my RX 7900 XT / RX 7900 XTX Linux review from launch day.

Interested developers can find the RDNA3 ISA documentation via GPUOpen.com.