Solana activated its Alpenglow consensus upgrade on testnet Sept. 24 and devnet Sept. 25, replacing TowerBFT with a new system called Votor. The overhaul targets transaction finality of 100 to 150 milliseconds, down from roughly 12.8 seconds today, but mainnet still has no launch date and key validator clients haven't added support yet.
Solana activated Alpenglow on public testnet Sept. 24, retiring the TowerBFT consensus mechanism in what is Solana's biggest consensus overhaul since launch. Anza, the company behind Solana's Agave validator client, oversaw a 5,000-slot countdown lasting about 17 minutes before the transition completed at slot 444,625,255. The final TowerBFT block carried 82% of stake before an Alpenglow genesis block handed finalization duties to Votor.
Devnet Follows a Day Later
Devnet completed its own transition Sept. 25, finishing at slot 504,148,999. A dedicated community cluster had rehearsed the switch since May, including one unsuccessful attempt that required a restart. Co-founder Anatoly Yakovenko marked the devnet activation with a five-word post: According to Bitcoin News: "You are not ready for this."
Votor Cuts Finality From Seconds to Milliseconds
Solana's existing system requires validators to submit votes as onchain transactions and wait through a 32-slot confirmation chain, a process that reportedly accounts for about 75% of network transaction counts. Votor instead moves voting offchain, collecting peer-to-peer votes into compact BLS certificates. A fast path targets 100 milliseconds when 80% of stake agrees in one round, while a fallback path targets 150 milliseconds if 60% agrees initially, followed by another round. The Solana Virtual Machine, transaction format and fees remain unchanged, so wallet users won't need to migrate anything.
Mainnet Still Faces Hurdles
Firedancer and Frankendancer haven't implemented Votor yet, leaving the first public transitions dependent on Agave 4.3. Anza wants developers testing integrations through an observation period before any mainnet-beta migration, and no firm activation date has been set. Solana Foundation's Ilan Gitter cited more than 25,000 transactions per second with 150-millisecond finality on the testnet cluster, though that figure comes from a test cluster rather than mainnet. Exchanges, bridges and custodians may also still process deposits using systems built around considerably longer confirmation periods.
Source: Bitcoin News
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