Reflection unveils Beam, a 501B open-weight MoE trained with RL on 10.5K GB300 GPUs

thione · x · 2026-10-12

Reflection introduced Beam, its first open-weight model: a sparse MoE with 501B total / 23B active parameters built for coding, reasoning, and agentic workloads.

The same recap notes Mistral previewed Large 4, a trillion-parameter model focused on cyber/enterprise work, also with open weights planned for late October.

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