Solana to activate Alpenglow on mainnet on October 21, cutting finality to 150 milliseconds

Solana will activate Alpenglow on mainnet around 15:00 UTC on October 21, retiring its current consensus mechanism and reducing finality from approximately 12.8 seconds to a target of about 150 milliseconds, an 85-fold increase in speed. The new system is designed to survive 20% of stake acting maliciously plus another 20% offline, enhancing resilience compared to the old system, which broke if over a third of staked SOL turned hostile. However, this change means Solana's headline transaction count and TPS figures will likely decrease as validators switch from casting votes as transactions to voting directly to each other.