AMD's RDNA4 GPU Architecture at Hot Chips 2025
6 hours ago
- #GPU
- #RDNA4
- #AMD
- RDNA4 is AMD’s latest graphics architecture, part of the RX 9000 series, focusing on efficiency in rasterization, compute, and raytracing.
- Machine learning workloads are a key focus for RDNA4, with improvements in both raytracing and ML performance.
- The Media Engine in RDNA4 offers faster decoding and better quality in H.265 and AV1 encoding, especially for low latency streaming.
- RDNA4’s display engine includes features like Radeon Image Sharpening and optimizations for multi-monitor idle power consumption.
- Compute improvements in RDNA4 include enhanced raytracing units, wider BVH nodes, and split barriers for better synchronization.
- The memory subsystem in RDNA4 features an 8 MB L2 cache, improved compression, and the removal of the L1 cache for efficiency.
- RDNA4 includes reliability and security features like RAS, ECC, and protected register access for critical blocks.
- Infinity Fabric is used in RDNA4 for coherent memory access, with 16 CS blocks and 4 MB cache per CS, supporting DVFS.
- AMD chose a monolithic design for RDNA4, optimizing for performance, cost, and turnaround time.
- RDNA4 focuses on efficiency over top-end performance, with improvements in raytracing, media, and display capabilities.