Can I run it?
Can I run gpt oss 20b on GeForce RTX 3060 12GB?
Expert offload
Expert offload on your GeForce RTX 3060 12GB: Q4_K_M keeps shared weights on the GPU and about 5.95 GB of experts in system RAM. About 58–79 tok/s. Active-parameter speed is approximate.
Best quantQ4_K_M
Working context8K
Max that fits8K
Speed58–79 tok/s
Weights10.8 GB
KV cache0.19 GB
Total5.47 GB
Usable10.9 GB
gpt oss 20b details · GeForce RTX 3060 12GB page · How this estimate is made
Run commands
llama.cpp
# Expert offload is approximate. llama.cpp can pin experts to CPU: # -ot "\\.ffn_.*_exps\\.=CPU" llama-server -hf unsloth/gpt-oss-20b-GGUF:Q4_K_M -c 8192 -ngl 99
No matching name in the Ollama library snapshot.
LM Studio
lms get unsloth/gpt-oss-20b-GGUF # Then load quant Q4_K_M
Assumptions
- Estimate, not a benchmark. Decode speed uses a memory-bandwidth model at 55–75% of peak.
- KV cache is FP16. Engine overhead assumes llama.cpp (0.3 GB + 1% of the weights). Ollama is closer to 0.9 GB + 3%, LM Studio closer to 1 GB + 3%.
- Q4_K_M size is the real GGUF file size from Hugging Face.
- 0.5 GB is reserved because this GPU also drives a display, then 5% of the rest is left free.
- Speed is quoted at 8K context, not at the maximum context that still fits.
- Mixture-of-experts split is approximate: shared layers on the GPU, expert tensors in system RAM. Speed uses active parameters.
Models that fit this machine more comfortably
- Can I run Qwen3.6 35B A3B on GeForce RTX 3060 12GB? — Tight fit, UD-IQ2_XXS, 180–246 tok/s
- Can I run Qwen3.5 35B A3B on GeForce RTX 3060 12GB? — Tight fit, UD-IQ2_XXS, 182–248 tok/s
- Can I run Qwen2.5 32B Instruct on GeForce RTX 3060 12GB? — Tight fit, IQ2_XXS, 20–27 tok/s
Updated 2026-10-17. Profile on this page is the device default plus 32 GB of DDR5-5600 system RAM.