Solana Begins Upgrade Tests That Could Reduce Finality Times by 98%

Solana has taken its Alpenglow upgrade to the public testnet, where developers will test whether transaction finality can be reduced from about 13 seconds to just 0.15 seconds.

A successful rollout would give exchanges, bridges and merchants a much faster way to determine that transactions are irreversible.

Finality marks the point at which a blockchain transaction is considered permanent. Exchanges generally wait for it before making deposits available, bridges require it before releasing assets on another network, and merchants use it to confirm that a payment cannot be reversed.

The Alpenglow upgrade is being tested on Solana’s public test network, which operates as a replica of the blockchain but uses tokens with no real financial value. This allows developers to run migration tests, identify problems and restart the network without putting actual user funds at risk.

Solana currently reaches consensus through TowerBFT. Validators record their votes onchain and build enough consensus across 32 slots before a block is considered final.

Alpenglow would replace TowerBFT with Votor, a new voting system designed to speed up consensus. Validators would send votes directly to each other, allowing a block to potentially become final after one or two rounds rather than relying on a long sequence of onchain votes.

For users, little would change at the application level. Existing applications could continue processing transactions normally, and users would not need to change wallets or modify how they transfer funds.

The upgrade has already undergone more than four months of testing on a smaller network built specifically for Alpenglow. Deploying it to Solana’s established testnet will provide a broader test of whether the network’s validators and supporting infrastructure can transition simultaneously.

The current test requires validators to run Agave 4.3, Solana’s main validator client maintained by Anza, one of the companies contributing to the network’s development.

Anza recommended Agave 4.3 to mainnet validators on Sept. 21 after gradually deploying it to operators accounting for 10% and then 25% of the SOL securing the network.

Jump Crypto’s alternative validator clients, Firedancer and Frankendancer, have not yet been added to the Alpenglow test.

Both alternatives are intended to increase software diversity across Solana’s validator network, reducing the risk that a problem in Agave could affect every validator simultaneously. Their lack of support means the initial Alpenglow migration will use Agave exclusively.

Anza’s schedule currently shows Sept. 28 as a provisional date for enabling the features included in Agave 4.3 on mainnet. However, this should not be treated as an official Alpenglow launch date. The company’s tracker still showed the testnet activation as pending early Wednesday.