Can RTX A6000 48GB run gpt-oss-20b?

NVIDIA · 48 GB GDDR6 · 768 GB/s bandwidth · OpenAI · 21.5B (active 3.6B) · MoE · model ctx up to 128K

Yes — the RTX A6000 48GB (48 GB GDDR6) can run gpt-oss-20b. At Q4 with the default 8K context it needs ≈ 13.55 GB VRAM (weights 11.83 GB + KV cache 0.72 GB + 1 GB runtime overhead), which fits within 48 GB. Decode at Q4/8K: ≈ 135.8 tok/s (estimated, batch 1). FP16 (≈ 44.72 GB) also fits, at ≈ 37.3 tok/s (estimated). 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	13.19 GB	Yes	135.8 est.
Q4	8K default	13.55 GB	Yes	135.8 est.
Q4	32K	15.71 GB	Yes	135.8 est.
FP16	4K	44.36 GB	Yes	37.3 est.
FP16	8K default	44.72 GB	Yes	37.3 est.
FP16	32K	46.88 GB	No	111.8 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	RTX A6000 48GB VRAM
Q4	11.83 GB	0.72 GB	1 GB	13.55 GB	48 GB
FP16	43.0 GB	0.72 GB	1 GB	44.72 GB	48 GB

Other GPUs that run gpt-oss-20b

• B200 192GB SXM — ≈1414.1 tok/s Q4 est.
• MI300X 192GB — ≈936.9 tok/s Q4 est.
• H200 141GB SXM5 — ≈848.5 tok/s Q4 est.
• H100 80GB SXM5 — ≈592.2 tok/s Q4 est.
• Gaudi 3 128GB — ≈579.1 tok/s Q4 est.
• A100 80GB SXM4 — ≈360.4 tok/s Q4 est.
• RTX 5090 32GB — ≈282.5 tok/s Q4 measured
• RTX 4090 24GB — ≈225.2 tok/s Q4 measured

All GPUs for gpt-oss-20b →

Other models for the RTX A6000 48GB

• Qwen3-0.6B — ≈610.9 tok/s Q4 est.
• gemma-3-1b-it — ≈488.7 tok/s Q4 est.
• Llama-3.2-1B-Instruct — ≈407.3 tok/s Q4 est.
• Qwen3-1.7B — ≈244.4 tok/s Q4 est.
• Qwen3-30B-A3B — ≈162.9 tok/s Q4 est.
• Qwen3-Coder-30B-A3B-Instruct — ≈162.9 tok/s Q4 est.
• GLM-4.7-Flash — ≈162.9 tok/s Q4 est.
• Qwen3-30B-A3B-Instruct-2507 — ≈162.9 tok/s Q4 est.

All models on the RTX A6000 48GB →