Run Reflection Beam 1.0 501B on a Dedicated Mac

Macs that run Reflection Beam 1.0 501B

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

• 2× Mac Studio M5 Ultra 256GB Cluster Best value Cluster
  34–46 tokens/sec
  from $2,399/mo Available Nov 16, 2026
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• Mac Studio M5 Ultra 512GB
  37–50 tokens/sec
  from $2,499/mo Available Dec 30, 2026
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• 2× Mac Studio M5 Ultra 512GB Cluster Cluster
  34–46 tokens/sec
  from $4,999/mo Available Dec 30, 2026
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• 4× Mac Studio M5 Ultra 512GB Cluster Cluster
  30–39 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.

Reflection Beam 1.0 501B is a mixture-of-experts model: of its 501 billion parameters, only about 23.4 billion are used for each word. It needs memory for all of them but runs at the speed of a much smaller model.