Solana’s Alpenglow upgrade replaced TowerBFT with Votor, changing how validators reach consensus and reducing the protocol’s stated finality target from about 12.8 seconds to roughly 150 ms. Solana confirmed it was live on mainnet on October 21, 2026, while the 150 ms figure is a target, not a measured post-launch result. Solana’s announcement

Solana’s Alpenglow upgrade replaced TowerBFT with Votor, changing how validators reach consensus and reducing the protocol’s stated finality target from about 12.8 seconds to roughly 150 ms. Solana confirmed it was live on mainnet on October 21, 2026, while the 150 ms figure is a target, not a measured post-launch result. Solana’s announcement

Votor replaces on-chain vote transactions with direct validator votes and aggregate certificates, enabling blocks to reach finality in one or two rounds. This is a consensus change; transaction execution and the SVM remain unchanged, so most apps need no migration. Solana Foundation’s overview

Rotor, which is planned to replace Turbine’s block-propagation system, is a later phase and was not part of this activation. Anza’s overview