Mistral Large 4 1T A52B NVFP4 — DGX Spark bring-up (2026-10-29/30)

mistralai/Mistral-Large-4-1T-A52B-NVFP4 — Mistral's 1T MoE (52B active), DeepSeek-style sparse MLA + DSA top-k indexer, cross-layer KV sharing, NoPE layers, embedded DSpark drafter (k=3), multimodal (Pixtral tower), native 1M context. Weights: 610 GB (568 GiB), NVFP4 experts + FP8 linears (modelopt MIXED_PRECISION). The NVFP4 repo has no config.json (only the FP8 checkpoint has one) — Mistral-native "consolidated" format.

Lanes: mistral-large4-nvfp4-8x-vllm, mistral-large4-nvfp4-8x-sglang (8× DGX Spark, TP8, 512K context, DSpark spec k=3 both). Reports: recipes/<lane>/reports/2026-10-30_*.

Images

Both vendor images ship arm64 variants — no source builds needed (the dsv41-style sm_121a rebuilds were NOT required; kernels JIT where missing):

docker-images/mistral-large4-vllm — thin FROM over vllm/vllm-openai@sha256:b046d936… (the mistral-large-4 tag, arm64 digest); ENTRYPOINT ["vllm","serve"], vLLM 0.1.dev23730+g64053a10b, torch 2.14.0+cu130.
docker-images/mistral-large4-sglang — thin FROM over lmsysorg/sglang@sha256:2f0cd825… (mistral-large-4 tag, arm64); NVIDIA wrapper /opt/nvidia/nvidia_entrypoint.sh + sglang serve CLI; torch 2.14.1+cu130, mistral_common 1.13.0. One baked patch (patch_barrier_timeout.py): the post-load monitored_barrier timeout becomes env-tunable (SGLANG_UNBALANCED_LOAD_TIMEOUT_S, default 480).

Recipe entrypoints: the launcher runs --entrypoint <tail[0]> img <tail[1..]>, so the recipes carry explicit entrypoints (vllm serve / the NVIDIA wrapper + sglang serve). Gotcha (latent launcher bug): a recipe WITHOUT entrypoint for a positional-model engine composes --entrypoint <model-id> — broken since the 2026-09-26 command.rs change (commit ad7069e). Every new recipe must lead the tail with its program.

Boot ledger (SGLang lane, 6 boots — the hard-won flags)

Boot	Result	Cause
1	died in ~1 s	containerd snapshotter lazy-unpack race: `docker load` returns before the rootfs is materialized; `docker run` 35 s later exec'd a half-unpacked image (`stat …: no such file`), `--rm` deleted the evidence, rendezvous hung 30 min. Launcher fix 0.2.5: sync probes exec-readiness per peer (`/bin/sh` container start, retried ≤2 min) before declaring OK.
2	head died at ~21 min, logs lost	KV-budget refusal at GMU 0.85 (see below); `--rm` destroyed the logs — all retries use `--keep` now.
3	weights loaded, crash at autotune	default flashinfer MLA route autotunes `trtllm fmha` — sm100-only ("Unsupported architecture" on GB10/sm_121).
4	rank 0 loaded (3.5 h), barrier killed ranks 2/5/6/7	`UNBALANCED_MODEL_LOADING_TIMEOUT_S = 480` stock; rank-0 crawl was self-inflicted (my mid-load `drop_caches` wiped the warm NFS page cache → cold re-read of 71 GB). Barrier now 7200 s via the baked patch.
5	weights loaded (80 min), crash at backend init	`flashinfer_sparse_mla` is GLM-DSA-only — the validator refuses any other `model_arch`.
6	weights + autotune OK, crash in a warmup forward	NVFP4 MoE auto-routed to the TensorRT-LLM runner on SM12x → `'FusedMoE' object has no attribute 'g1_scale_c'` (upstream #41764/#45520: the auto rule compares `--quantization`, unset for checkpoint-quantized models).
7	READY	`--moe-runner-backend flashinfer_cutlass` (the supported NVFP4 MoE runner on SM120/121).

The flags that matter (SGLang)

--tokenizer-mode mistral          # NVFP4 has no config.json: AutoTokenizer→AutoConfig
                                  # dies ("couldn't find them in the cached files");
                                  # mistral-common (tekken.json) instead
--attention-backend dsa           # DSA backend (MistralLarge4AttentionMLA extends
                                  # DeepseekV2AttentionMLA)
--dsa-prefill-backend tilelang    # tilelang JIT-compiles for sm_121; FP8 KV REQUIRES
--dsa-decode-backend tilelang     # both backends tilelang (layouts cannot be mixed)
--moe-runner-backend flashinfer_cutlass   # NVFP4 MoE on SM120/121
--watchdog-timeout 3600           # boot takes ~80 min
SGLANG_UNBALANCED_LOAD_TIMEOUT_S=7200     # post-load barrier

vLLM lane flags

--config-format mistral --load-format mistral --kv-cache-dtype fp8_ds_mla --dtype bfloat16 --enable-expert-parallel --enable-prefix-caching --mm-processor-cache-gb 0.0 --tool-call-parser mistral --reasoning-parser mistral --enable-auto-tool-choice --speculative-config '{"method":"dspark","num_speculative_tokens":3}' + GMU 0.89.

GMU boot-1 lesson: at 0.85 the KV budget after weights (73.8 GiB) + graph profiling (5.0) is 23.63 GiB — a single 512K request needs 25 GiB ("estimated maximum model length is 495296"). 0.89 = +4.9 GiB and still under the GB10 admission ceiling (108.78 GiB free at startup). Explicit cudagraph capture sizes (the dsv41 boot-10 lesson) backfired here: 29 exact sizes ate +3.6 GiB of graph memory — auto sizes win.

GB10 UMA page-cache accounting (verified live)

The UMA driver's mem_get_info free ≈ MemFree, not MemAvailable — page cache from the NFS weight reads (~30 GB) counts as unavailable (#48140 behaviour, SGLang side): GPU-free fell to ~1.6 GiB mid-load with MemAvailable still 31 GB, and a mid-load drop_caches released ~20 GiB instantly (verified). BUT wiping the warm NFS cache forces a cold re-read of 71 GB — rank 0's load went 40 min → 3.5 h. Do NOT drop_caches mid-load; keep the NFS cache warm and let the load converge. The post-load barrier must be longer than the slowest rank's crawl.

Bench (tool-eval-bench v3.0.0, seed 42, hardmode, c1/c2, from pluto)

Same model id (mistral-large-4), 512K, DSpark k=3 on both.

Metric	vLLM (`…8x-vllm`)	SGLang (`…8x-sglang`)
Quality	91/100 (174/192)	91/100 (176/194)
Deployability	70	71
Responsiveness (median turn)	6.9 s	6.5 s
pp2048 @d0	1,069	897
pp2048 @d0 c2	837	925
tg @d0 c1/c2	24.8 / 33.0	31.9 / 41.7
ctx pp4096 @d4096 c1/c2	1,204/20.9 · 1,068/29.8	1,066/25.0 · 1,001/36.1
pp2048 @d4096 c1/c2	1,310/20.9 · 980/30.7	1,077/31.6 · 919/43.7
ctx pp8192 @d8192	1,286	1,117
pp2048 @d8192 c1/c2	1,268/22.0 · 984/31.0	1,047/32.4 · 804/38.1

SGLang decode is faster everywhere (+25-45% tg: 31.9 vs 24.8 c1; 41.7 vs 33.0 c2 at d0; 43.7 vs 30.7 at d4096 c2) — the tilelang DSA decode + DSPARK stack.
vLLM prefill is faster (+19-22% pp) — its TRITON_MLA/FlashInfer prefill path.
Quality identical (91/100). vLLM's TC-45 probe (tool_choice) failed with finish_reason=length and was excluded (174/192); SGLang's endpoint enforces tool_choice (176/194) — a real capability difference.
Safety-critical: vLLM 2 (TC-81 injection, TC-92 tenant isolation); SGLang 3 (the same two + TC-74 batched sends).

Bottom line: for agentic decode-heavy traffic SGLang is the faster engine; for prefill-heavy long-context batch vLLM. Both are production-viable at 512K.

mistral-large4-bringup.md 7.1 KB تاريخچه خام