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

User reports Qwen3.8-27B Flash-Next at 433.19 t/s prompt processing and 27.72 t/s generation on a Tesla V100 32GB, comparing a custom llama.cpp fork against vanilla llama.cpp. Setup is llama.cpp (v100-optimized fork) with UD-Q5_K_XL GGUF, q8_0 K/V cache, 262144 context, FlashAttention on, MTP n-max=3, 63 GPU layers, 100000 cached tokens plus a 1000-token appended prompt. The fork gains +43.94% prompt processing at 100k cached + 1k appended (300.94 to 433.19 t/s) and +32.19% generation with the MTP3 decode stack (27.591 to 36.471 t/s), while standard llama-bench tg128 is effectively unchanged (27.89 to 27.72 t/s).