Estimates from memory-bandwidth formula; rows marked "measured" override. Methodology.
Fit & speed by quant and context
Quant
Context
VRAM needed
Fits?
tok/s (decode)
Q4
4K
67.06 GB
Yes
177.7±est.
Q4
8K default
67.12 GB
Yes
177.7±est.
Q4
32K
67.48 GB
Yes
177.7±est.
FP16
4K
241.06 GB
No
15.4±est.
FP16
8K default
241.12 GB
No
15.4±est.
FP16
32K
241.48 GB
No
15.3±est.
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).
VRAM breakdown at 8K context
Quant
Weights
KV cache
Overhead
Total needed
H100 80GB SXM5 VRAM
Q4
66.0 GB
0.12 GB
1 GB
67.12 GB
80 GB
FP16
240.0 GB
0.12 GB
1 GB
241.12 GB
80 GB
Other GPUs that run NVIDIA-Nemotron-3-Super-120B-A12B-BF16