DeepSeek V4.1 Flash 552B (16B active)

User reports DeepSeek-V4.1-Flash at 87.7 tok/s single-stream decode on four NVIDIA DGX Sparks (TP=4). Setup is SGLang with native MXFP4 experts and FP8 dense weights, DSpark speculative decoding (k=5), 1M context configured, 8M-token KV pool pinned, ~77 GiB resident weights per rank. Aggregate decode reaches 342.7 tok/s at 16 streams (22.2 per stream); cold prefill is 4,059-5,925 tok/s at 4k-262k context, 4.9k-5.0k tok/s on real text at 16k-128k. A 1,011,084-token needle test passed. The 3-Spark TP=3 profile is also documented at 37.9 tok/s single-stream.