Can the AMD Radeon RX 7900 XTX run gpt-oss 20B?

Radeon RX 7900 XTX × gpt-oss 20B8K context
YesRuns fully on the GPU
Memory at Q8_023.2 GB of 24 GB
Weights 22.2 GBKV cache 0.4 GBRuntime 0.6 GB
QuantQ8_0Near-lossless
Memory23.2 GBof 24 GB usable
Speed~151tokens per second
  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 AMD Radeon RX 7900 XTX can run gpt-oss 20B fully in VRAM at Q8_0 (near-lossless), using about 23.2 GB of the 24 GB available, at roughly 151 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 13.7 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 Radeon RX 7900 XTX

Run it in the cloud

No AMD Radeon RX 7900 XTX? 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 AMD Radeon RX 7900 XTX can use.

QuantQualityMemoryFits?Speed
FP16Full quality42.8 GBToo big—
Q8_0Near-lossless23.2 GBFits~151 tok/s
Q6_KExcellent18.1 GBFits~195 tok/s
Q5_K_MVery good15.9 GBFits~225 tok/s
Q4_K_MGood, most popular13.7 GBFits~264 tok/s
Q3_K_MNoticeably degraded11.2 GBFits~327 tok/s
Q2_KHeavily degraded8.8 GBFits~427 tok/s

Frequently asked questions

Can AMD Radeon RX 7900 XTX run gpt-oss 20B?

Yes. The AMD Radeon RX 7900 XTX can run gpt-oss 20B fully in VRAM at Q8_0 (near-lossless), using about 23.2 GB of the 24 GB available, at roughly 151 tokens/second.

How much VRAM does gpt-oss 20B need?

About 13.7 GB at Q4_K_M with 8,192 tokens of context, and about 42.8 GB at full FP16 precision.

How fast is gpt-oss 20B on the AMD Radeon RX 7900 XTX?

Roughly 151 tokens per second at Q8_0, estimated from the AMD Radeon RX 7900 XTX's 960 GB/s memory bandwidth.