howtospark
models / LibertAIDAI/Hy3-NVFP4
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172B params~17B activemodeloptMoE 192×8GQA 64:8MTP ×1262K ctxother
Sparks
~105 GB
~68 GB
~66 GB
~63 GB
110 usable
REAP dialno pruning · 192 experts
Spec decode
Context33K / 262KKV
On the Sparks — 1× · 2-bit experts + NVFP4 dense · 33K ctx · FP16 KV~176K ctx fits usable
spark
47 GB free
Expert planes41.7* GB2-bit
110 usable
63* / 110 GB
57% of usable
Expert planesDense weightsKV cacheActivations + graphsOS reserve

* segment sizes marked with an asterisk are estimates pending a measured run

Estimated per-node footprint, weights + KV sharded across the Spark (tensor parallel). Overhead ~8 GB/node; KV at FP16.

layer map
80 layersMoE FFN
in
out

one MoE layer · 192 experts, 8+1 fire per token

each expert ≈ 11M params

resident: 80 MoE layers × 192 experts × 11M 166.8B

active/token: 80 × 8 × 11M 12.1B experts

+ 5.2B always-on dense (attention, embeddings, shared stack) = 17.2B active

Recipes (all recipes)

Worked deployments that run this model on DGX Spark — each shows how it fills each node's unified memory.

Optimize
Quantized from

tencent/Hy3

Analyze the original repo for the full architecture picture.

Verdict

172B params, ~86 GB at already modelopt-quantized — fits on one Spark as-is.

Make it fast

Once it fits: fewer bytes per token and fewer decode steps against 273 GB/s.

Use its MTP heads

Ships 1 multi-token-prediction layer(s) — self-speculative decode with no separate draft model; check vLLM/SGLang support for this arch.

Prune experts for speed

Fewer experts ⇒ smaller working set ⇒ better cache/page behavior, even when it already fits.

Tame the KV cache

At 262144 tokens the KV cache alone is ~86 GB at FP16; quantize or evict.

Make it yours

Change what the model does — adapt, edit, or steer it — independent of size.

Fine-tune it

LoRA/QLoRA adapts behavior on one Spark without touching the base weights.