I ported EXL3 to run well on Apple Silicon - PonyExl3

In three linesEXL3 codec ported to Apple Silicon using Metal backend. M5 Max achieves ~600 tok/s prefill and ~38 tok/s generation (Qwen 27B), outperforming RTX 4090 on some benchmarks (68.5-80 tok/s decode). GitHub repo with reproducible results.

Summary generated by Claude — human-verified