AMD · 16 GB GDDR6 · 624 GB/s bandwidth ·
Google · 11.95B · model ctx up to 256K
Yes — the RX 7800 XT 16GB (16 GB GDDR6) can run gemma-4-12b-it. At Q4 with the default 8K context it needs ≈ 9.96 GB VRAM (weights 6.57 GB + KV cache 2.39 GB + 1 GB runtime overhead), which fits within 16 GB. Decode at Q4/8K: ≈ 33.2 tok/s (estimated, batch 1). FP16 needs ≈ 27.29 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
8.77 GB
Yes
33.2est.
Q4
8K default
9.96 GB
Yes
33.2est.
Q4
32K
17.13 GB
No
82.8est.
FP16
4K
26.09 GB
No
9.8est.
FP16
8K default
27.29 GB
No
9.0est.
FP16
32K
34.46 GB
No
5.6est.
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).