Seven days. That is how long Solana’s validators have before Alpenglow replaces TowerBFT, the voting system the network has run since its 2020 launch, according to the updated timetable the Solana Foundation published and CoinDesk reported on 14 October.
The migration is scheduled for epoch 1064, expected to begin around 15:00 UTC on 21 October. The old system stays in place for the first 5,000 slots, and Alpenglow takes over roughly 18 minutes later.
The change is in how blocks get finalised. Validators currently submit votes as on-chain transactions. Under Alpenglow they exchange votes directly and combine enough approvals into a certificate that finalises a block after one or two voting rounds. The target is about 150 milliseconds, and CoinDesk stressed that real performance will depend on network conditions.
Faster finality matters to anyone who needs a payment to be irreversible rather than merely visible. Merchants and cross-chain bridges are the examples cited.
There are side effects. Vote transactions leave the blocks, so Solana’s reported transaction count could drop sharply on activation day even if nobody uses the network any less. Validators must run software built on Agave 4.3.0, and operators of the alternative Firedancer and Frankendancer clients will have to switch temporarily because neither supports the initial migration.
The economics change too. Voting charges of roughly 1 SOL per epoch disappear and are replaced by a flat admission fee of 0.8 SOL.
The part to watch is the first week of data. A figure that dives on a chart will be an accounting artefact, and whether the finality number holds outside a test network is the claim that has not yet been measured.
