DeepSeek V4 Flash 284B (13B active)

User reports DeepSeek V4-Flash-0731 at 33 tok/s single-stream on 2x RTX 3090 in a used quad-Xeon R940 server with 768 GB DDR4. Setup is the Lvllmds4-x vLLM fork with the official MXFP4 safetensors checkpoint, fp8_ds_mla KV cache, 32K context, and DSpark speculative decoding with 5 draft tokens. Aggregate throughput is 53-68 tok/s at 4 concurrent requests and 47-63 tok/s at 8, with per-user rates of 13-17 and 6-8 tok/s. Cold prefill plateaus at 420-480 tok/s, warm prefill reaches 2,030-10,200 tok/s, and the same box on ik_llama.cpp hybrid does 12.2 tok/s single-stream. The user notes the bottleneck is CPU-side DRAM bandwidth, not the GPUs.