Run gpt-oss-20b on a Dedicated Mac

Macs that run gpt-oss-20b

At 4-bit (as released) with a 32K-token context. Speeds are estimates; see real measurements on the calculator page.

• Mac Mini M6 32GB Best value
  29–40 tokens/sec
  from $169/mo
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• Mac Mini M5 Pro 64GB
  49–67 tokens/sec
  from $299/mo
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• Mac Studio M4 Max 128GB
  78–102 tokens/sec
  from $499/mo
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• Mac Studio M5 Max 128GB
  86–111 tokens/sec
  from $569/mo Available Nov 10, 2026
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• Mac Studio M5 Ultra 256GB
  136–167 tokens/sec
  from $1,199/mo Available Nov 16, 2026
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• 2× Mac Studio M5 Ultra 256GB Cluster Cluster
  107–125 tokens/sec
  from $2,399/mo Available Nov 16, 2026
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• Mac Studio M5 Ultra 512GB
  136–167 tokens/sec
  from $2,499/mo Available Dec 30, 2026
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• 2× Mac Studio M5 Ultra 512GB Cluster Cluster
  107–125 tokens/sec
  from $4,999/mo Available Dec 30, 2026
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• 4× Mac Studio M5 Ultra 512GB Cluster Cluster
  75–83 tokens/sec
  from $9,999/mo Available Dec 30, 2026
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Why it runs well on a Mac

Language models have to sit entirely in memory, and generating each word means reading through them again. Apple Silicon puts up to 512 GB of fast unified memory on one chip that the GPU can use directly, so a model like this fits on one quiet machine instead of a stack of graphics cards.

gpt-oss-20b is a mixture-of-experts model: of its 21 billion parameters, only about 3.6 billion are used for each word. It needs memory for all of them but runs at the speed of a much smaller model.