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
16.6 GB
Yes
88.8±est.
Q4
8K default
19.0 GB
Yes
88.8±est.
Q4
32K
33.4 GB
Yes
88.8±est.
FP16
4K
51.4 GB
Yes
24.4±est.
FP16
8K default
53.8 GB
Yes
24.4±est.
FP16
32K
68.2 GB
Yes
24.4±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
13.2 GB
4.8 GB
1 GB
19.0 GB
80 GB
FP16
48.0 GB
4.8 GB
1 GB
53.8 GB
80 GB
Other GPUs that run Devstral-Small-2-24B-Instruct-2512