AMD RDNA4 GPU 架构，详细解读！

Core Viewpoint - AMD's RDNA4 architecture represents significant advancements in efficiency for gaming GPUs, particularly in ray tracing and machine learning workloads, while also improving rasterization performance [2][4][55]. GPU Architecture Improvements - RDNA4 introduces enhancements in ray tracing and machine learning efficiency, alongside improvements in rasterization [4]. - The architecture is designed with future workloads in mind, focusing on optimizing performance for the next five years [2]. Media Engine Enhancements - The media engine in RDNA4 supports hardware-accelerated video encoding and decoding, with a focus on improving quality for H.265, H.264, and AV1 codecs, particularly in low-latency scenarios [5][7]. - RDNA4's media engine shows superior performance in video quality metrics, such as Netflix's VMAF, across various bitrates [10]. Display Engine Features - The display engine in RDNA4 includes a "Radeon Image Sharpening" filter that enhances image quality without impacting performance, utilizing dedicated hardware for efficiency [13]. - Power consumption optimizations in the display engine target multi-monitor setups, allowing for dynamic refresh rate adjustments to save energy [14][15]. Compute Changes - RDNA4 retains the advanced layout of previous generations while introducing significant improvements in ray tracing units and memory management [16]. - Scalar floating point instructions have been expanded to enhance performance and reduce power consumption by offloading constant operations [18][20]. Memory Subsystem Enhancements - The architecture features an increased L2 cache size of 8 MB, which benefits high-demand workloads like ray tracing [23]. - RDNA4 employs transparent compression techniques across the system-on-chip (SoC) to reduce memory bandwidth usage and improve efficiency [29][42]. SoC Features - RDNA4 incorporates reliability, availability, and serviceability (RAS) features, including error detection and correction mechanisms [43]. - The architecture supports dynamic voltage and frequency scaling (DVFS) to optimize power consumption [51]. Infinity Fabric Integration - The Infinity Fabric in RDNA4 facilitates efficient memory access and consistency between CPU and GPU components, enhancing overall performance [49][51]. Conclusion - RDNA4 achieves a balance between performance and efficiency, with improvements in ray tracing, media encoding, and power management, while maintaining a compact chip size [55][58].