Wire
Reflection unveils a 501B open-weight model
Reflection unveiled Beam, a 501-billion-parameter open-weight model with 23 billion active, and claims it matches GLM-5.2 on advanced reasoning benchmarks while using 3–4× less inference compute, according to the company’s launch post and TechCrunch’s report. The weights and technical report are still due later this month, so the efficiency claim is not yet independently reproducible. Builders comparing local inference can use the open-weight development path illustrated by MiniMax M2.7 as context, but should keep Beam off a production route until its artifacts and independent tests arrive.