Solana activates Alpenglow, targeting 150ms finality

Solana activated Anza’s Alpenglow upgrade on Oct. 21, changing how validators agree on transactions and aiming to cut finality to about 150 milliseconds. Finality is the point when a transaction is considered settled and cannot be reversed under the protocol. The Block reported that Alpenglow reached mainnet-beta at slot 459,653,000 at about 14:00 UTC, replacing TowerBFT, Solana’s consensus system since its 2020 launch.

The 150-millisecond figure is a target, not a guarantee for every payment. Anza’s comparison puts finality at about 12.8 seconds under the old system. Faster finality could let exchanges credit deposits and merchants accept payments sooner, though the wait users see also depends on the services they use.

How does Alpenglow change validator voting?

Alpenglow moves validator votes off the blockchain and lets validators exchange them directly, then combine approvals into certificates. Under TowerBFT, votes were recorded as transactions and approvals accumulated across successive blocks. CoinDesk’s report says the new system can make a block final after one or two voting rounds.

This replaces the way validators agree on blocks; it does not change how Solana apps execute transactions. Wallets, fees and applications remain unchanged, according to CoinDesk. An exchange or payment service can use faster finality as a stronger signal that a payment is settled, but the upgrade does not itself make every app display that status sooner.

Why could Solana transaction counts fall?

Validator votes no longer appear as on-chain transactions, so dashboards that count those votes may show lower totals after the switch. That drop would not by itself mean users are making fewer payments or trades. The old totals included validator voting activity alongside user transactions.

Solana’s new consensus system is called Votor, the voting part of Alpenglow. Anza has also outlined Rotor, a separate planned change to how block data spreads across the network. The Block reported that Rotor has no confirmed release date. For now, the live change is Alpenglow’s replacement of TowerBFT and its attempt to make transaction settlement much quicker.

References

• The Block reported — theblock.co
• CoinDesk’s report — coindesk.com