howtospark
models / LiquidAI/LFM2.5-8B-A1B-Base
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8.5B params~1.3B activebfloat16MoE 32×4GQA 32:8128K ctxother
Sparks
~27 GB
~22 GB
~18 GB
~14 GB
~12 GB
~12 GB
~12 GB
110 usable
REAP dialno pruning · 32 experts
Spec decode
Context33K / 128KKV
On the Sparks — 1× · 2-bit experts + NVFP4 dense · 33K ctx · FP16 KV~2.0M ctx fits usable
spark
98 GB free
110 usable
12* / 110 GB
11% 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
24 layersconv×18full attention×6
in
out

one MoE layer · 32 experts, 4 fire per token

each expert ≈ 11M params

resident: 24 MoE layers × 32 experts × 11M 8.2B

active/token: 24 × 4 × 11M 1.1B experts

+ 254M always-on dense (attention, embeddings, shared stack) = 1.3B active

Optimize
Verdict

8B params, ~17 GB at bfloat16 — fits on one Spark as-is.

Make it fit

Get the weights (and headroom for KV) inside the 128 GB pool — the hard gate.

Lossless compression

BF16 weights entropy-code ~30% smaller bit-exact — smaller downloads and less bandwidth per token, no quality question at all.

Make it fast

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

Add a speculative decoder

Decode is bandwidth-bound at ~104.1 tok/s ceiling; a trained EAGLE-style draft multiplies tokens per weight-read.

Prune experts for speed

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

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.