Solana Alpenglow Upgrade Achieves 54ms Finalization on Testnet

Solana's Alpenglow upgrade has launched on its public testnet, achieving a median block finalization time of 54 milliseconds, significantly faster than the 100-150ms target and the current mainnet average of 12.8 seconds. The upgrade introduces Votor, a new consensus mechanism that moves voting off-chain using BLS-signed certificates to reduce block space consumption. The update also implements dual finalization paths and a 20+20 fault-tolerance model while maintaining existing transaction formats and fee structures. The proposal, SIMD-0326, was approved by validators in September 2025 with 98.27% support, though a mainnet deployment date remains undecided.