GLM-5.3 320B (18B active) Flash

User reports GLM-5.3-Flash Q4_K at 6.21 t/s decode and 2.60 t/s prefill on an M4 Max 128 GiB via SSD streaming. Setup is ds4 with Q4_K GGUF, 4096 context, 128-token protocol, cold and warm runs. The 177.77 GiB model streams from SSD; GPU time is only ~24 ms of ~161 ms per token (15%), with host-side per-layer expert-cache bookkeeping dominating. Removing the synchronous selected-id readback changed nothing (6.22/6.24 t/s, byte-identical output). MTP was ~15% slower (5.28/5.22 t/s). Cache budgets of 48/56/85 GB gave 5.3/5.3/4.6 t/s; the automatic 70.1 GiB budget was best. All tested flags stayed within noise of 6.2 t/s.