Solana Tests Alpenglow Upgrade for Faster Transaction Finality

Solana is taking its Alpenglow upgrade to the public test network to speed up transaction finality. This change could let exchanges and merchants treat payments as effectively irreversible sooner, while leaving user transactions unchanged.

The Alpenglow upgrade replaces TowerBFT with Votor, a protocol that lets validators send votes directly to one another and finalize blocks after one or two rounds. This cuts out the longer chain of on-chain voting that currently takes around 13 seconds. The result could be finality in just 150 milliseconds.

Validators participating in the initial migration need Agave 4.3, which has been rolled out to operators responsible for 10% and then 25% of network SOL as of Sept. 21. However, the first Alpenglow migration does not support Firedancer or Frankendancer validator clients.

The test run is intended to show whether the wider set of computers and services that already run the blockchain can switch together under broader operating conditions. A tentative but unconfirmed mainnet feature date is Sept. 28, although this has not been confirmed.