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

User reports Qwen3.8-Flash-Next at 24.5 tok/s decode on code without MTP on a single DGX Spark (GB10, 121 GB unified). Setup is llama.cpp (danielhanchen qwen4exp/mtp branch) with UD-Q4_K_XL GGUF weights (103.7 GiB), 131,072 context, flash attention on and CUDA graphs active, with about 95 GB used serving. With the Q8_0 shared MTP draft at --spec-draft-n-max 4, decode reaches 47.1 tok/s on code, 36.9 on thinking and 24.2 on prose. A 77,527-token voxel-pagoda run finished in 51 min at 25.3 tok/s end to end.