Solana is switching on its biggest network overhaul since 2020 at the start of epoch 1064, with the actual change set for slot 459,653,000 after a 5,000-slot transition.

Alpenglow replaces on-chain validator voting with off-chain vote certificates that can lock in a transaction in one or two rounds. Today validators write votes to the chain like regular transactions, and finality takes about six seconds.

Target finality drops to roughly 150 milliseconds, about 40x faster than today.

Validators also lose the roughly 2 SOL a day they spend on vote fees, replaced by a flat admission ticket of 0.8 SOL per epoch (about 60% cheaper). The road was rough: the test network was restarted six times since May, and one migration attempt failed network-wide before a later one succeeded.