Solana to Activate Alpenglow Upgrade on October 21

Alpenglow is less a speed bump than a rewrite of Solana's consensus plumbing: removing vote transactions from blocks changes what validators actually do and how blockspace is consumed, which matters more to infrastructure operators and app builders than the headline finality figure. The 150-millisecond target, if sustained under real load, would put Solana's confirmation experience closer to centralized venues than to other L1s, a distinction that tends to matter most for trading and payments use cases. Whether the upgrade performs as designed outside test conditions is the open question.