Solana is set to activate the Alpenglow consensus mechanism on its mainnet on October 21 at approximately 15:00 UTC. This update replaces the system used since the network launch. The transition aims to reduce transaction finality from about 12.8 seconds to a target of 150 milliseconds, representing an 85-fold increase in speed.
The new mechanism is designed to maintain finality even if 20% of the staked SOL acts maliciously and another 20% goes offline, improving upon the previous threshold where the system would fail if more than one-third of the stake turned hostile. Anza, the core development team, stated the migration represents 18 months of development work.
The update will change how validators cast votes. Instead of submitting votes as on-chain transactions, validators will communicate directly with each other. This shift is expected to significantly lower the network's reported transaction count and TPS figures, although actual user activity and volume will remain unchanged.
This deployment marks the first of two planned phases, with no date currently set for the second part. The Alpenglow activation was previously scheduled for September 28 before being delayed to the current date.
