Summary
User reports Qwen3.8 Flash-Next at 57 t/s decode and 1239 tok/s encode on Strix Halo 128GB.
Setup uses MTP speculative decoding; the run processed 6204 chunks in 119.0 s.
User says the prefill speed is twice that of the fastest Strix Halo-specific llama.cpp fork they have used, and greater still versus mainline llama.cpp.