Gemma 4's mixture-of-experts model holds about 26B parameters but activates only 3.8B — so it's quick, and it fits a 16GB card at Q4. The VRAM math, the GPU, and the run command.
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Gemma 4 26B-A4B is the family's clever middle option: a mixture-of-experts model that stores about 26B parameters but only activates 3.8B per token. You get closer-to-large capability with the speed of a much smaller model, and — unusually for a 26B — it fits a 16GB card at Q4.
What Gemma 4 26B-A4B actually is
From Google's model card (read 26 Sep 2026): multimodal for text and image, a 256K context, and — per the card's MoE table — 3.8B active parameters out of 8 active experts of 128 (plus 1 shared). Open weights, licensed Apache-2.0 (per the model card on Hugging Face). On total size, the card headlines 25.2B for the core model; our VRAM engine counts the full model at about 26.5B, which is what the computed pages below use. Its config.json shows the MoE structure and Gemma's usual sliding-window attention (25 of 30 layers), so both compute and KV cache stay lean. The "A4B" in the name is those active parameters — 3.8B per token.
The same MoE caveat applies as for any mixture-of-experts model: 3.8B active is about speed, not storage. All ~26.5B parameters load into VRAM (or offload to RAM). The good news is that quantised to Q4, that total still lands around 16 GB.
That combination is what makes this the interesting one in the family. A dense model with genuinely strong capability usually asks for a 24GB card; here you get a ~26B-parameter model that runs on a mainstream 16GB card at Q4, and runs quickly because only 3.8B parameters fire per token. It's the closest thing Gemma 4 has to a "punches above its VRAM" pick. The trade-offs are the ones every MoE carries: the 16GB fit is real but tight, so long multimodal prompts want more headroom, and the storage is a 26B's storage even though the speed is a 4B's speed.
The Gemma 4 family at a glance (params as our VRAM engine counts the full model; modality and context from Google's cards, read 26 Sep 2026)
Gemma 4 26B-A4B VRAM by quant (computed, 16K context)
Q4_K_M
Total VRAM (full weights)
~16.1 GB
Q6_K
Total VRAM (full weights)
~21.4 GB
Q8_0
Total VRAM (full weights)
~27.4 GB
BF16 (full)
Total VRAM (full weights)
~50 GB
Total VRAM (full weights)
Q4_K_M
~16.1 GB
Q6_K
~21.4 GB
Q8_0
~27.4 GB
BF16 (full)
~50 GB
At ~16.1 GB, Q4_K_M is a tight-but-real fit for a 16GB card (leave context modest). A 24GB card runs it with comfortable headroom, and if your GPU is smaller, MoE offload will fit it on 12GB at the cost of speed — see the MoE offload guide.
Because it's a mixture of experts, the same offload trick that helps the big Qwen applies here: if 16GB feels tight, push some experts to system RAM and the model still runs, just more slowly. But the nicer story is that you rarely need to. At Q4 this ~26B model already fits a mainstream 16GB card, which is the entire reason to reach for it over a dense model of similar strength — you get the capability without the 24GB entry ticket, and the 3.8B active parameters keep it quick while you're at it.
A 16GB RTX A4000 was listing from about $0.072/hr, and a 24GB RTX 3090 from about $0.139/hr, on Vast.ai's spot market (26 Sep 2026). Prices move; check the live figure before you rent.
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How to run it
ollama run gemma4:26b # the 26B-A4B MoE
# smaller GPU? offload experts with llama.cpp:
llama-server -hf <gemma4-26b-a4b-GGUF> --n-cpu-moe 16
As with the other Gemmas, name the size — the bare gemma4 tag pulls the small e4b. gemma4:26b gives the MoE model; --n-cpu-moe offloads idle experts to RAM if your card is under 16GB.
Who should skip it
Skip Gemma 4 26B-A4B if you have a 24GB card and want maximum quality — a dense Gemma 4 31B activates every parameter for a similar VRAM budget. Skip it if you're on a 12GB card and want simplicity; Gemma 4 12B runs there without offload. And treat the 16GB Q4 fit as real but tight — if you run long multimodal prompts, plan for a 24GB card.
Gemma 4 26B-A4B: common questions
How much VRAM does Gemma 4 26B-A4B need?
About 16.1 GB at Q4_K_M (computed by our VRAM engine, 16K context), a tight fit for a 16GB card. Q6 needs ~21 GB.
What does 'A4B' mean?
3.8 billion parameters are active per token (the card's figure), even though the model holds about 26B in total. It's a mixture-of-experts model, so it's fast for its size.
Does the MoE design lower its VRAM?
No — all ~26.5B parameters load into VRAM (or offload to RAM). The active count affects speed, not memory. At Q4 the full weights are ~16 GB.
What's the best GPU for Gemma 4 26B-A4B?
A 16GB card like the RTX 4060 Ti 16GB at Q4, or a 24GB card for headroom. See our best-GPU page for live prices.