Can RTX 5090 run gpt-oss 20B?

Q: Can RTX 5090 run gpt-oss 20B?

Yes. Measured 324.2 tok/s generation on RTX 5090, via llama.cpp 0.7.0-dev, reported as Q4_K_M. Source: https://llm-speed.com/r/r_dwp5fgdapmw

Yes. Measured 324.2 tok/s generation (llama.cpp 0.7.0-dev, reported as Q4_K_M; source).

Every measured result for gpt-oss 20B on RTX 5090

Build	Quant / setup	Engine	tok/s
RTX 5090 (llm-speed signed runs, Oct 2026): gpt-oss 20B 324 tok/s, Qwen3.8 27B 75 tok/s	reported as Q4_K_M	llama.cpp 0.7.0-dev	324.2	source
RTX 5090: 2026 models (llamabench community)	llama-bench tg128 (quant per result)	llama.cpp	313	source
Single RTX 5090 32GB	MXFP4	llama.cpp	282.51	source

Memory: RTX 5090 has 32 GB. gpt-oss 20B weights are about 13 GB in its native format (GGUF param count via llamabench.ai (OpenAI model card: 21B total, 3.6B active)). Arithmetic, not a measurement; long contexts need more. Check other quants in the VRAM calculator.

Speeds are decode (generation) tokens/sec as reported by each source; quant, engine and context differ, so small gaps are noise.

All measured speeds for gpt-oss 20B: best home rig for gpt-oss 20B.

gpt-oss 20B on other hardware: Apple M1 Max · Apple M1 Ultra · Apple M2 Ultra · Apple M3 Ultra · Apple M4 Max · DGX Spark (GB10) · RTX 3060 12GB · RTX 3090 · RTX 4070 Ti · RTX 4090 · RTX 5060 Ti 16GB · RTX 5070 Ti · RTX 5080 · RTX A4000 · RTX Pro 6000 (Blackwell, 96 GB) · RTX Spark N1X · Radeon AI Pro R9700

Other models measured on RTX 5090: DeepSeek V4.1 Flash · GLM-5.3 Flash · Gemma 4 12B · Gemma 4 26B-A4B · Gemma 4 31B · Ornith 1.5 122B · Qwen3.5 9B · Qwen3.6 27B · Qwen3.6 35B-A3B · Qwen3.8 27B · Qwen3.8 Flash-Next

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