The Solana network has scheduled the Alpenglow upgrade for October 21, coinciding with the start of epoch 1064 at approximately 15:00 UTC. This update replaces the current TowerBFT consensus mechanism with a new system designed to significantly reduce transaction finality times.
Under the new Votor protocol, transaction finality is expected to drop from the current 12.8 seconds to approximately 150 milliseconds. The system allows validators to communicate directly off-chain, enabling block finalization after one or two rounds of voting, provided they meet specific stake thresholds.
The transition includes a stability period where TowerBFT remains active for 5,000 slots, or roughly 18 minutes, before Alpenglow fully takes control at slot 459,653,000. The upgrade does not alter the Solana Virtual Machine, transaction formats, or existing fee structures for users.
Validators are required to pay a new Validator Admission Ticket fee of 0.8 SOL per epoch, which will be burned. This replaces the previous system where validators spent approximately 1 SOL per epoch on vote transaction fees. Validators unable to cover this cost will be excluded from voting and block production.
The Alpenglow upgrade was approved by validators in September 2025 with 98.27% of the vote. The October 21 release introduces Votor, while the second component, Rotor, which replaces the Turbine data broadcasting system, is scheduled for a later date.
