How much VRAM does Gemma 3 12B IT need?

About 9.3 GB at Q4_K_M with 4K of context and batch 1, rising to roughly 20.1 GB at 32K. That figure is weights plus KV cache plus a 10% activation buffer, calculated from the model's architecture rather than measured on a card.

Will Gemma 3 12B IT run on a 12GB GPU?

Yes — at Q4_K_M and 4K context it needs about 9.3 GB, which leaves 2.7 GB spare on a RTX 5070. That is the smallest card in this index that clears it comfortably; 55 of 63 do.

Which quantization of Gemma 3 12B IT should I use?

Q5_K_M has the lowest published quality loss (1.3%), and Q4_K_M is the level most people run. All 3 levels in the index are Q4_K_M, Q5_K_M, AWQ INT4.

Gemma 3 12B IT

12B

Google Gemma 3

Mid-size Gemma 3 with vision. Fits 16GB at Q4; excellent multilingual chat.

Consumer GPUMac / Apple Silicon

131K

Max Context

Quant Variants

GGUF Q5_K_M

Best Quality

98.7%

Accuracy Retained

Calculate VRAM Hugging Face Compare

Quantization Variants

Per-quant VRAM, quality loss, and inference speed on RTX 4090

Measured = site benchmarks · Estimated = formula · Community = public reports

Format	Level	BPW	VRAM	PPL Loss	Speed	Source	Actions
GGUF	Q4_K_M	4.85	8.8 GB	2.9%	105 tok/s	Estimated	Calc HF
GGUF	Q5_K_M	5.68	10.2 GB	1.3%	92 tok/s	Estimated	Calc HF
AWQ	INT4	4	8.0 GB	3.9%	128 tok/s	Estimated	Calc HF

Similar models

Compare with Gemma 3

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27B

Gemma 3 27B IT

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Qwen2.5 14B Instruct

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The sweet spot between performance and resource usage. 16GB VRAM with Q4.

Running Gemma 3 12B IT locally

At Q4_K_M and 4K of context, Gemma 3 12B IT needs about 9.3 GB — 7.0 GB of weights, 1.41 GB of KV cache and a 0.8 GB activation buffer. The smallest card in this index that clears that comfortably is the RTX 5070 at 12 GB, and 55 of the 63 cards here do. These are calculated figures, not measurements: the estimate stops counting a card as comfortable at 88% of its VRAM, which is roughly the room a desktop session needs.

What longer context costs

Going from 4K to 32K adds about 9.84 GB, taking the total to 20.1 GB. Weights do not move with context — only the KV cache does, and it grows linearly, so this is the number to watch when planning for long documents. The model's native window is 128K; holding all of it at Q4_K_M would need about 57 GB.

Which build to download

This index tracks 2 formats for it — GGUF, AWQ — across 3 levels. Q5_K_M carries the lowest published perplexity loss at 1.3%. The fastest level measured here is AWQ INT4 at 128 tok/s on an RTX 4090, batch 1. GGUF runs on llama.cpp and Ollama across NVIDIA, AMD and Apple silicon; AWQ and GPTQ target vLLM on CUDA and ROCm; EXL2 is ExLlamaV2 and CUDA only.

Common questions

How much VRAM does Gemma 3 12B IT need?: About 9.3 GB at Q4_K_M with 4K of context and batch 1, rising to roughly 20.1 GB at 32K. That figure is weights plus KV cache plus a 10% activation buffer, calculated from the model's architecture rather than measured on a card.
Will Gemma 3 12B IT run on a 12GB GPU?: Yes — at Q4_K_M and 4K context it needs about 9.3 GB, which leaves 2.7 GB spare on a RTX 5070. That is the smallest card in this index that clears it comfortably; 55 of 63 do.
Which quantization of Gemma 3 12B IT should I use?: Q5_K_M has the lowest published quality loss (1.3%), and Q4_K_M is the level most people run. All 3 levels in the index are Q4_K_M, Q5_K_M, AWQ INT4.

Where this model fits

Sized at Q4_K_M with a 4K context window, smallest card first. Comfortable means the estimate uses at most 88% of the memory.

Runs comfortably on: RTX 507012GB · +2.7 RTX 4070 Ti12GB · +2.7 RTX 4070 Super12GB · +2.7 RTX 407012GB · +2.7 RTX 3080 Ti12GB · +2.7
Tight but possible: RTX 3080 10G10GB
Just misses: RTX 3070+1.3GB over Mac M3 8G+3.3GB over
Ships in: GGUF AWQ
Compared here: GGUF vs AWQ
A top pick for: Best local LLM for 12GB
Try it yourself: Size it in the calculator Generate the run command

How to actually run this

Deployment guides for this model and this class of hardware.

This page's figures change when the model or the runtime does.Last updated 2026-09-23 RSS → /feed.xml