Can the NVIDIA RTX 3090 Ti run gpt-oss 20B?

RTX 3090 Ti × gpt-oss 20B8K context
YesRuns fully on the GPU
Memory at Q8_023 GB of 24 GB
Weights 22.2 GBKV cache 0.2 GBRuntime 0.6 GB
QuantQ8_0Near-lossless
Speed~158tokens per second
Max context46Ktokens that fit at Q8_0
  1. FP16
  2. Q8_0
  3. Q6_K
  4. Q5_K_M
  5. Q4_K_M
  6. Q3_K_M
  7. Q2_K

Yes. The NVIDIA RTX 3090 Ti can run gpt-oss 20B fully in VRAM at Q8_0 (near-lossless), using about 23 GB of the 24 GB available, at roughly 158 tokens/second.

Run it with Ollama

With Ollama installed, one command downloads and starts gpt-oss 20B:

ollama run gpt-oss:20b

Ollama's default download is Q4_K_M (about 13.5 GB here). You have room for Q8_0, which is near-lossless: pick that GGUF in LM Studio or from Hugging Face.

New to this? Step-by-step setup for the RTX 3090 Ti

Run it in the cloud

No NVIDIA RTX 3090 Ti? Run gpt-oss 20B in the cloud.

Rent a cloud GPU by the hour. No upfront cost, stop any time.

Memory needed by quantization

At 8,192 tokens of context. The black line marks the 24 GB the NVIDIA RTX 3090 Ti can use.

QuantQualityMemoryFits?Speed
FP16Full quality42.6 GBToo big—
Q8_0Near-lossless23 GBFits~158 tok/s
Q6_KExcellent17.9 GBFits~205 tok/s
Q5_K_MVery good15.7 GBFits~236 tok/s
Q4_K_MGood, most popular13.5 GBFits~277 tok/s
Q3_K_MNoticeably degraded11 GBFits~344 tok/s
Q2_KHeavily degraded8.6 GBFits~448 tok/s

Measured speed from real RTX 3090 Ti owners

Tokens per second that people measured on their own NVIDIA RTX 3090 Ti, next to our estimate.

No one has measured gpt-oss 20B on the NVIDIA RTX 3090 Ti yet. The speeds above are estimates. Run the benchmark and yours becomes the first real number on this page.

Have an RTX 3090 Ti? Add your real speed

One command times gpt-oss 20B in your own Ollama, shows you exactly what it would send, and asks before sending anything. No sign-up, no personal data.

macOS and Linux

curl -fsSL https://gpufit.dev/bench.sh | sh -s -- gpt-oss:20b

Windows (PowerShell)

$env:GPUFIT_MODEL="gpt-oss:20b"; irm https://gpufit.dev/bench.ps1 | iex

How the benchmark works

Frequently asked questions

Can NVIDIA RTX 3090 Ti run gpt-oss 20B?

Yes. The NVIDIA RTX 3090 Ti can run gpt-oss 20B fully in VRAM at Q8_0 (near-lossless), using about 23 GB of the 24 GB available, at roughly 158 tokens/second.

How much VRAM does gpt-oss 20B need?

About 13.5 GB at Q4_K_M with 8,192 tokens of context, and about 42.6 GB at full FP16 precision.

How fast is gpt-oss 20B on the NVIDIA RTX 3090 Ti?

Roughly 158 tokens per second at Q8_0, estimated from the NVIDIA RTX 3090 Ti's 1008 GB/s memory bandwidth.