Reflection unveils Beam: a 501B-parameter open-weight MoE model benchmarking between Qwen 3.8 and GLM 5.2

gethackteam · x · 2026-10-06

Reflection announced Beam, its first open-weight model: a sparse MoE with 501B total / 23B active parameters, built for coding, reasoning, and agentic workloads. It claims frontier Western open-weight performance, competitive with GLM 5.2 and approaching Qwen 3.8-Max.

Pretraining used 23.8T curated tokens, plus a 4-week high-compute RL run generating 100M+ rollouts on 10.5K NVIDIA GB300 GPUs. Weights, tech report, and model card ship later this month after final red-teaming. This tweet is gethackteam's repost noting Beam sits between Qwen 3.8 and GLM 5.2 on benchmarks.

Related event: Reflection AI Debuts Beam, a 501B-Parameter Open-Weight Model(20 posts)→

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