Qwen3.8 125B (6B active) Flash-Next

User reports Qwen3.8-Flash-Next at 38 t/s serial decode and 1,311 t/s prefill on a Strix Halo 128GB (Ryzen AI Max+ 395, Radeon 8060S) box. Setup is halogen 0.17.1 with a 262k context, MTP speculative decoding on, and the model fully in unified memory; the same run reaches 64 t/s with MTP and 72.7 t/s aggregate across two concurrent streams. A llama.cpp ROCm build with qwen4exp MTP reached 47 t/s, and halogen 0.16.2 gave 42-46 t/s with NPU calls 30x slower. The NPU sidecar handles search, dedup, decisions and screening; a keyword-poor task averaged 13.6 min with NPU retrieval against 18.7 min without.