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

User reports DeepSeek V4.1 Flash at 97.23 tok/s for a single interactive request on eight RTX 5090 32GB GPUs over PCIe with no NVLink. Setup is vLLM with MXFP4 quantization, 32,768-token context, TP8 plus expert parallelism, and 9-11 GiB/rank of decoder expert offload to host RAM (503 GiB installed, about 264-279 GiB shared). Aggregate output reaches 247.77 tok/s at eight concurrent requests and 368.55 tok/s at 128 concurrent text requests; 8K prefill at two concurrent requests is 3,145 tok/s. The checkpoint is about 476 GiB and its quantization is unchanged.