howtospark
models / LiquidAI/LFM2.5-24B-A2B-Base
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24B params~2.2B activebfloat16MoE 64×4GQA 32:8131K ctxother
Sparks
Users
~59 GB
~47 GB
~35 GB
~23 GB
~18 GB
~17 GB
~17 GB
110 usable
REAP dialno pruning · 64 experts
Spec decode
Context33K / 131KKV
On the Sparks — 1× · 2-bit experts + NVFP4 dense · 33K ctx · FP16 KV~1.2M ctx fits usable · ~35 users fit
spark
93 GB free
110 usable
17* / 110 GB
15% 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
40 layersconv×30full attention×10
in
out

one MoE layer · 64 experts, 4 fire per token

each expert ≈ 9M params

resident: 40 MoE layers × 64 experts × 9M ≈ 23.3B

active/token: 40 × 4 × 9M ≈ 1.5B experts

+ 719M always-on dense (attention, embeddings, shared stack) = 2.2B active

Optimize
Verdict

24B params, ~48 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 ~61.2 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.

Tame the KV cache

At 131072 tokens the KV cache alone is ~11 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.