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

User reports Qwen3.8 Flash-Next at 70 t/s generation and 1.3k t/s prefill on 4x V620 (128GB total VRAM) at 128k+ context. Setup is a vLLM fork with AutoRound W4A16 quantization and MTP-2 speculative decoding, on an EPYC 7452 with 256GB DDR4. Prose generation runs at 60 t/s. Power draw is 700-900W during prefill and 500-600W during decode. User was initially disappointed with Qwen3.8 27B speeds but is satisfied with Flash-Next.