Richard Geldreich's Blog: Large block size ASTC has been misunderstood

Rich Geldreich argues that large block size ASTC (10x10, 12x12) has been widely misunderstood by game developers. These block sizes were designed for high-resolution (4K) content and offer dramatic memory bandwidth savings (0.89–1.28 bpp). GPU shader deblocking at these sizes is essentially free on mobile/tablet hardware where memory bandwidth is the bottleneck. He notes that existing encoders are incomplete or broken — Intel's ispc_texcomp lacked multi-subset support and is now archived, while ARM's LDR encoder lacks deblocking awareness and supercompression support. The path forward involves deblocking-aware encoders that exploit deblocking like modern image/video codecs have done for decades.