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

User benchmarks Qwen3.8-Flash-Next 8-bit on a Mac Studio M5 Ultra 256GB, reporting 17 t/s decode and 1,069 t/s prefill at 250k context on llama.cpp (Metal). Setup is llama.cpp with Q8_0 weights and MTP off; oMLX 0.7.0rc1 reaches 51 t/s decode and 1,365 t/s prefill at the same depth, and 88 t/s decode at 10k with MTP on. A cold 250k-token prompt took 234 s before the first token, while the cached next step took 0.64 s. DeepSeek-V4-Flash at 400k and 500k context took 934 s and 1,311 s cold. The user notes one overnight agent run per setup and that the DeepSeek engine comparison mixes two model variants.