Sybil AI
‹ RTX PRO 6000 Blackwell

DeepSeek-V4.1-Flash

· vllm.512k.4x.moet-r13 · 512K context · 4 × RTX PRO 6000 Blackwell in one machine · 384 GB

DeepSeek's V4.1 Flash, a large mixture-of-experts model.

138 tok/sdecode
8,944 tok/sprefill
512Kcontext window
Reported by 0xSeroOct 21, 2026
Run it

This is the launch as 0xSero publishes it. Their repository has the full setup: sybil-solutions/local-ai-recipe-kit@321e7a4ffe9e › The server then answers on http://localhost:8000/v1.

  1. 1 Set up first
    # NEEDS (measured on the reference host with the recipe kit's memwatch, before launch to peak): 4x RTX PRO 6000 Blackwell 96 GB (sm_120) in ONE machine with GPU peer-to-peer over PCIe (cudaDeviceCanAccessPeer true for every pair; the P2P all-reduce and NCCL_P2P_LEVEL=SYS rely on it), 368,132 MiB VRAM in use at ready (0.94) / 387,916 MiB peak; host RAM: 47 GB MemAvailable drop at peak (32 GiB of it is the pinned KV offload region, which lives in the container's /dev/shm, hence --shm-size 48g); disk: 510.3 GB of weights on local NVMe (Engram rows are read from the checkpoint at every decode step) + the 9.6 GB image; the KV disk tier writes into the container's own filesystem (/srv/kvcache) and goes away with it. FIRST START: FlashInfer autotune + DeepGEMM JIT run in the container (~22 min upstream, nothing is cached across --rm containers); then 9.69M GPU KV tokens (18.5x concurrency at 524,288). MEASURED on the reference host (Threadripper PRO 9965WX, 125 GiB RAM, PCIe 5.0, 300 W per GPU, stock memory clock; same vLLM-Moet 5d25cff + engram_disk build tagged locally, warm caches, a serving box with other agent traffic during the sweep): recipe kit sweep, natural completions, no output caps (https://github.com/sybil-solutions/local-ai-recipe-kit/blob/321e7a4ffe9e627d5bb899fb83ecada5deb57580/submissions/4x-rtx-pro-6000-96gb/2026-10-21-0xSero.json): prefill 8k 8,944 / 16k 9,937 / 32k 10,695 / 64k 11,119 tok/s; decode C1 137.6, C2 191.7, C3 202.5, C4 263.2, C8 271.7 tok/s aggregate (prose), C1 at 32k 73.1 tok/s. vLLM-Moet's single-stream code bench (tools/sm120_perf/fraser_bench.py, 2,048 tokens, 10 reps, 2026-10-21): median 403 tok/s (live traffic), undisturbed reps 557-573 tok/s at 5.4-5.6 accepted tokens per step; upstream reports 641 median / 686 best at 325 W with +5000 MHz memory and the Engram table in host RAM. QUALITY vs a stock-kernel reference (the same image with every VLLM_MOET_* switch 0, fp8_ds_mla KV, fp8 indexer, default MoE, no speculative decoding; 8 prompts, 1,953 teacher-forced positions; https://github.com/sybil-solutions/local-ai-recipe-kit/blob/321e7a4ffe9e627d5bb899fb83ecada5deb57580/targets/deepseek-v4.1-flash-4x-rtx-pro-6000.md): top-1 agreement 0.974, mean KL 0.0195 (reference vs itself 0.9995 / 0.00019); needle PASS at 245K and 510K. Lossy by design: the FP4 KV record, MXFP4 indexer keys, b12x 8-bit MoE activations and the MXFP8 target lm_head; every other switch is bit-identical to the path it replaces (VLLM_MOET_*=0 falls back to stock). Decode is power-bound: record the GPU power limit with any number.
    # Full instructions: https://github.com/sybil-solutions/local-ai-images/tree/9b79a61a06dc4d7e21c1b0be4b3e302eb0b7281d/vllm-moet-dsv41
  2. 2 Download the weights
    hf download deepseek-ai/DeepSeek-V4.1-Flash-1017 \
      --revision 1bae0e1088993b9b82de08f59de5be5a34e42170 \
      --local-dir ~/models/DeepSeek-V4.1-Flash-1017-1bae0e10
  3. 3 Start the server
    docker run --rm \
      --gpus all \
      -p 8000:8000 \
      --ulimit memlock=-1:-1 \
      --cap-add IPC_LOCK \
      --shm-size 48g \
      -e HF_HUB_OFFLINE=1 \
      -e NCCL_P2P_DISABLE=0 \
      -e NCCL_P2P_LEVEL=SYS \
      -e TRANSFORMERS_OFFLINE=1 \
      -e VLLM_ENGINE_READY_TIMEOUT_S=3600 \
      -e VLLM_MOET_B12X_MOE_FUSED=1 \
      -e VLLM_MOET_ENGRAM_DISK=1 \
      -e VLLM_MOET_ENGRAM_DISK_THREADS=16 \
      -e VLLM_MOET_P2P_AR=1 \
      -e VLLM_MOET_P2P_AR_FUSED_MAX_ROWS=16 \
      -e VLLM_MOET_SPARSE_MLA_LDG=1 \
      -e VLLM_MOET_TARGET_LM_HEAD_MXFP8=1 \
      -v ~/models/DeepSeek-V4.1-Flash-1017-1bae0e10:/models:ro \
      --entrypoint vllm \
      ghcr.io/sybil-solutions/vllm-moet-dsv41@sha256:08f61e680ddab3f1f1b50f92020133c382630f9798ab0ff5729f8931a604f82d \
      serve \
      /models \
      --served-model-name deepseek-v4.1-flash \
      --host 0.0.0.0 \
      --port 8000 \
      --tensor-parallel-size 4 \
      --max-model-len 524288 \
      --gpu-memory-utilization 0.94 \
      --max-num-seqs 8 \
      --kv-cache-dtype nvfp4_ds_mla \
      --tool-call-parser deepseek_v41 \
      --enable-auto-tool-choice \
      --reasoning-parser deepseek_v41 \
      --tokenizer-mode deepseek_v41 \
      --max-num-batched-tokens 4096 \
      --max-cudagraph-capture-size 64 \
      --speculative-config '{"method":"dspark","num_speculative_tokens":7,"draft_sample_method":"probabilistic","rejection_sample_method":"block","enable_adaptive_verification":false,"moe_backend":"b12x"}' \
      --attention-config '{"indexer_kv_dtype":"mxfp4","indexer_tp_shard_min_rows":2048}' \
      --moe-backend b12x \
      --kv-offloading-size 32 \
      --kv-transfer-config '{"kv_connector":"OffloadingConnector","kv_role":"kv_both","kv_connector_extra_config":{"spec_name":"TieringOffloadingSpec","secondary_tiers":[{"type":"fs","root_dir":"/srv/kvcache/v41-interleaved","n_read_threads":16,"n_write_threads":16,"locality":"LOCAL"}],"offload_prompt_only":false}}'
What it passed
– loadLoads and serves within an hour
– chatAnswers a plain question and stops on its own
– reasoningThinks separately and gets 17 × 23 right
– toolsCalls a tool with the right arguments and uses the result
– contextRecalls a code buried in a prompt that fills 85% of the window
– speedDecodes at 15 tok/s or more

Published by 0xSero in sybil-solutions/local-ai-recipe-kit@321e7a4ffe9e, where it reports 137.6 tok/s. Our six checks have not run on it yet.

Details
Weights
deepseek-ai/DeepSeek-V4.1-Flash-1017 @ 1bae0e1088 ›
Image
ghcr.io/sybil-solutions/vllm-moet-dsv41@sha256:08f61e680ddab3f1f1b50f92020133c382630f9798ab0ff5729f8931a604f82d
Source
sybil-solutions/local-ai-images @ 9b79a61a06dc4d7e21c1b0be4b ›
Launch
vllm-moet-deepseek-v4.1-flash-1017-512k-tp4 ›
Recipe file
registry/recipes/nvidia/rtx-pro-6000-blackwell-96gb/deepseek-v4.1-flash.vllm.512k.4x.moet-r13.json ›
Model released
Sep 10, 2026
Tested
not yet by us; reported by 0xSero