Solana has officially introduced Alpenglow, a major upgrade to its consensus protocol that significantly increases transaction finality speed.
The new system replaces TowerBFT and Proof-of-History (PoH) with two new components, Votor and Rotor, enabling block confirmations in just 100 to 150 milliseconds.
Built for Real-Time Applications
With Alpenglow, Solana moves closer to matching the speed of centralized platforms like PayPal or Google, but with a decentralized structure. The upgrade is especially important for applications that require fast feedback, such as gaming, digital payments, and trading systems. Before this, Solana’s average block finality time was over 12 seconds — now it’s cut to less than a second.
Introducing Votor and Rotor
The Alpenglow upgrade simplifies and accelerates the network’s structure. Votor handles validator voting and determines when a block is finalized. Rotor is responsible for moving data efficiently across the global validator network. Together, they streamline communication and cut down the steps needed for confirmation.
Solana now runs both voting rounds at the same time. If 80% of validators respond quickly, the block is finalized in one round. If fewer respond, a second round completes the process. The network doesn’t wait to choose between them, it confirms whichever path finishes first.
Global Testing Proves the Speed
To test the upgrade, Solana conducted a network-wide latency test with a lead validator based in Zurich, Switzerland. Results showed that 65% of network stake finalized blocks in under 200 milliseconds. Most delays were no longer due to software, but physical distance, confirming that Alpenglow is operating near the limits of real-world speed.
Alpenglow is designed to stay stable even if 20% of validators act dishonestly and another 20% fail to respond. It uses low-variance sampling to select validators fairly and avoids overloading any single node. Compared to older systems, the new model reduces network hops, simplifies message relays, and removes time-based limitations.