NVIDIA · 24 GB GDDR6X · 936 GB/s bandwidth ·
Google · 12.2B · model ctx up to 128K
Yes — the RTX 3090 24GB (24 GB GDDR6X) can run gemma-3-12b-it. At Q4 with the default 8K context it needs ≈ 10.11 GB VRAM (weights 6.71 GB + KV cache 2.4 GB + 1 GB runtime overhead), which fits within 24 GB. Decode at Q4/8K: ≈ 49.6 tok/s (estimated, batch 1). FP16 needs ≈ 27.8 GB — does not fit on this card. Estimates come from memory-bandwidth math; rows tagged measured override estimates. Relative ranking is more reliable than absolute tok/s. Methodology.
Fit & speed by quant and context
Quant
Context
VRAM needed
Fits?
tok/s (decode)
Q4
4K
8.91 GB
Yes
49.6est.
Q4
8K default
10.11 GB
Yes
49.6est.
Q4
32K
17.31 GB
Yes
49.6est.
FP16
4K
26.6 GB
No
31.7est.
FP16
8K default
27.8 GB
No
29.1est.
FP16
32K
35.0 GB
No
18.3est.
Fits = weights + KV(ctx) + 1 GB overhead ≤ 95% of VRAM. Measured
anchors are context-agnostic; the fit verdict is recomputed per context. A missing tok/s
means the model is far beyond this card (offload-only territory).