Solana sets Oct. 21 for Alpenglow upgrade targeting 150-millisecond finality

Solana has scheduled Oct. 21 for Alpenglow, a major upgrade aimed at making transactions irreversible in roughly 150 milliseconds by changing how the computers running the network agree on payments. The updated timetable published by the Solana Foundation sets a date for replacing TowerBFT, the voting system Solana has used since its launch in 2020. The 150-millisecond figure remains a target, with actual performance depending on network conditions. This matters as a Solana payment can already appear successful almost immediately. But Alpenglow aims to offer a stronger guarantee that it cannot be undone almost as quickly.