Solana Switches On Alpenglow, Targeting 150-Millisecond Finality

Solana’s biggest network overhaul since 2020 switches on Wednesday. The upgrade is expected to cut transaction finality to about 150 milliseconds from roughly six seconds, around 40 times faster than today. If the target holds on mainnet, a payment would settle in less time than a blink. By comparison, Ethereum takes about 13 minutes to reach full finality.

How the New Voting System Works

The change affects how validators, the computers that process transactions and vote on which ones are valid, reach agreement. Today every validator writes its votes onto the blockchain like any other transaction, and a payment is only locked in once enough votes stack up. Alpenglow moves that voting off the chain and bundles the votes into certificates that can lock in a transaction in one or two rounds. That brings Solana closer to the feel of a card payment or a trade on a centralized exchange.

Lower Costs for Validators

Validators currently spend about 2 SOL a day on vote fees, a cost that doubled after Solana cut slot times to about 200 milliseconds. Alpenglow replaces those fees with a flat validator admission ticket of 0.8 SOL per epoch, which lasts about 24 hours. That makes it roughly 60% cheaper.

A Rocky Road to Launch

The test network was wiped and restarted six times since early May, and one migration attempt failed network-wide and had to be rolled back, according to Galaxy Digital, one of roughly 100 validator operators on the test network. A later migration went through, clearing the way for Wednesday’s launch.