Solana core developer Anza announced on October 13 that the network plans to begin activating its Alpenglow consensus upgrade on October 21. The change aims to cut transaction finality from about 12.8 seconds to roughly 150 milliseconds, but that speed is a target, not a measured mainnet result. Actual finality will depend on network conditions, validator participation and the number of voting rounds.
Activation is scheduled to begin around 15:00 UTC, but the network will keep using its current system for about 18 minutes before attempting the switch. The handover requires validators representing at least 82% of staked SOL to sign a certificate, and user transactions will briefly stop being included in blocks during the transition. Validators need Agave 4.3.0 software and sufficient funds for a new participation fee; Firedancer and Frankendancer clients will not be supported during the migration. A separate change to block distribution is planned for a later release.
