DeepSeek V4 Flash 284B (13B active)

User reports DeepSeek V4 Flash 0731 at 44-47 tok/s decode on one NVIDIA DGX Spark (GB10, 128 GiB unified memory). Setup is vLLM with EXL3 3.0 bpw weights, NVFP4 KV cache, 384k context, DSpark K5 speculative decoding with a K64 draft model, single sequence. The 44-47 tok/s is a range. A 370,104-token stress test achieved exact needle recall with 0 preemptions, prefill ~625 tok/s effective, 594 s end-to-end. KV pool is 439,622 tokens.