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Solana activates Alpenglow, targeting 150ms finality

Solana activated Anza’s Alpenglow consensus upgrade, targeting 150ms finality as validators replace TowerBFT and shift block votes off-chain on mainnet.

The Top Crypto Editors 2 min read

Solana activates Alpenglow, targeting 150ms finality

Has Solana cut transaction finality to 150 milliseconds? Anza says Alpenglow went live on mainnet-beta on October 21, replacing TowerBFT at slot 459,653,000. The Anza announcement gives the new figure as a target: transactions are designed to become irreversible in roughly 150ms, down from about 12.8 seconds under TowerBFT. That is the time to finality, not the interval between blocks.

For you, the change matters when an app needs to know a payment is settled, such as an exchange crediting a deposit. The number is not a guarantee that every transaction will finalize in exactly 150ms: CoinDesk reports that actual timing depends on network conditions and how quickly services receive finality information. Solana says wallets, transaction fees and application execution remain unchanged.

How does Alpenglow change validator consensus?

Alpenglow’s Votor protocol replaces on-chain vote transactions with votes validators send directly to one another, which they combine into certificates. According to the Solana Foundation’s technical overview, a block can become final after one or two voting rounds. The fast path needs votes representing 80% of stake in one round; if it misses that threshold, a second round uses 60% thresholds to determine whether to finalize or skip the block.

This changes consensus, not transaction execution: the Solana Virtual Machine, programs and fees are untouched. It also means vote transactions no longer appear in blocks, so dashboards that counted them may show lower transaction totals even if user activity has not fallen. The 150ms claim should therefore be read as a protocol target, while each observer’s measured wait can vary.

What Solana upgrade comes next?

Anza’s next named change is Rotor, which is intended to replace Turbine’s block-propagation mechanism with a single relay layer. The Solana Foundation says Rotor is planned for a later release now that Votor is live, but no release date has been scheduled. Watch for Anza to publish that timing.

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