Measured model
Measured on a Mac Studio (M5 Max, 36GB)gpt-oss:20b
OpenAI
On a Mac Studio (M5 Max, 36GB), gpt-oss:20b answers a simple question in about 1.9 s, gets 81% of the Japanese knowledge questions right, 86% of the math problems, and uses 12.8GB of memory.
Results
| Measure | Result | Among measured models | Note |
|---|---|---|---|
| Reply time | about 1.9 s | 13 of 30 | Until one simple common-sense question is answered (median of 50) |
| Knowledge (high school to university) | 81% | 10 of 30 | 200 questions, ±6 |
| Math (word problems) | 86% | 7 of 30 | 100 questions, ±8 |
| Memory used | 12.8GB | 15 of 30 | |
| EN→JA translation | 33 pts | 8 of 28 | out of 100 (chrF), about 4.1 s a sentence |
| JA→EN translation | 55 pts | 17 of 28 | out of 100 (chrF), about 3.3 s a sentence |
"Among measured models" is the place among the 30 models measured on this site (lower is better for time and memory).
Try it on your Mac
- Install the Mac version of Ollama from ollama.com and start it.
- Type this in Terminal. The first time, the model downloads; then you can chat with it.
ollama run gpt-oss:20b
It used 12.8GB here. To use it comfortably alongside other apps, a Mac with 32GB of memory or more is a good guide (the model then takes about half the memory).
About the model
- Maker
- OpenAI
- Size
- 20.9B parameters
- Quantization
- MXFP4
- Thinks before answering
- Yes
- Longest input at once
- 131,072 tokens
- Released (Hugging Face)
- Aug 4, 2025
- Generation speed
- 92.6 tok/s
- Start-up (loading)
- about 4.4 s
- Measured on
- Oct 2, 2026
- Ollama
- 0.34.3
- Hugging Face
- openai/gpt-oss-20b
- Series
- gpt-oss
Models of similar memory
- LFM2-24B-A2B (14.8GB of memory, knowledge 54%, reply about 0.1 s)
- Ministral-3-14B-Instruct-2512 (9.9GB of memory, knowledge 72%, reply about 0.1 s)
- Devstral-Small-2-24B-Instruct-2512 (16.3GB of memory, knowledge 66%, reply about 0.2 s)
- Mistral-Small-3.1-24B-Instruct-2503 (16.3GB of memory, knowledge 72%, reply about 0.2 s)
- Mistral-Small-3.2-24B-Instruct-2506 (16.3GB of memory, knowledge 77%, reply about 0.2 s)
Compare the main models on the text page. The series page lists every model measured.