Best Gemma 4 12B quant for a 16GB GPU

Short answer: Q8_0 from unsloth. Of the 6 Gemma 4 12B files we tested that fit fully in 16GB with a 8192-token context, it has the highest measured accuracy (89.2% on GSM8K + MMLU + ARC-C, 95% CI 86.2–91.6). KLD pending: ranked by accuracy for now.

Smallest diff that fits 16GB
Q8_0 by unsloth
File size
11.80 GB
KLD
pending
Accuracy (500 items)
89.2% (86.2–91.6)
Tool calls
87.0%
Accuracy
tied with best
Generation
14 t/s GPU+RAM split

Speed was measured split on our 12GB test GPU. This file fits fully in 16GB, so expect it to run noticeably faster on your card.

gemma-4-12b-it-Q8_0.gguf
Runner-up
Q6_K by unsloth
File size
9.11 GB
KLD
pending
Accuracy (500 items)
88.2% (85.1–90.7)
Tool calls
86.0%
Accuracy
tied with best
Generation
57 t/s full GPU
gemma-4-12b-it-Q6_K.gguf
Fastest that fits
UD-Q2_K_XL by unsloth
File size
4.34 GB
KLD
pending
Accuracy (500 items)
67.2% (63.0–71.2)
Tool calls
58.5%
Accuracy
▼ below best on GSM8K, MMLU, ARC-C
Generation
98 t/s full GPU
gemma-4-12b-it-UD-Q2_K_XL.gguf

Other budgets: 8GB12GB24GB · all 6 Gemma 4 12B quants

How we picked

We estimate VRAM need as file size + f16 KV cache for 8192 tokens + about 0.6GB of compute buffers, and keep 0.5GB free for your desktop. Among files that fit, we rank by mean KL divergence against the BF16 model's logits, then by tool-call score. If you need a longer context, step down one quant level or quantize the KV cache (-ctk q8_0 -ctv q8_0). Methodology.

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