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models / google/gemma-4-26B-A4B
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google/gemma-4-26B-A4B
26B params~3.1B activebfloat16MoE 128×1GQA 16:8262K ctxmultimodalapache-2.0
Sparks
Users
~68 GB
~55 GB
~42 GB
~29 GB
~23 GB
~25 GB
~23 GB
110 usable
REAP dialno pruning · 128 experts
Spec decode
Context33K / 262KKV
On the Sparks — 1× · 2-bit experts + NVFP4 dense · 33K ctx · FP16 KV~386K ctx fits usable · ~11 users fit
spark
87 GB free
110 usable
23* / 110 GB
21% 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
30 layerssliding window×25full attention×5
in
out

one MoE layer · 128 experts, 1 fire per token

each expert ≈ 6M params

resident: 30 MoE layers × 128 experts × 6M ≈ 22.8B

active/token: 30 × 1 × 6M ≈ 178M experts

+ 3.0B always-on dense (attention, embeddings, shared stack) = 3.1B active

Optimize
Verdict

26B params, ~52 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 ~43.4 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.