Reflection AI's Beam: A 501B Open-Weight Bet on Efficient Reasoning
Reflection AI has unveiled Beam, a 501-billion-parameter text-only mixture-of-experts model with just 23 billion active parameters, trained on 23.8 trillion tokens with a 1-million-token context window. The company's headline claim: Beam matches GLM-5.2 on reasoning while using three to four times less inference compute. The weights are expected later in October under Apache 2.0, once red-teaming wraps up. In a market obsessed with parameter counts, Beam is a bet that the number on the box matters less than the number actually doing work.
