Solana has activated the first phase of a major network upgrade that reduces its mainnet target slot time from 400 milliseconds to 350 milliseconds, moving one step closer to an eventual 200ms goal.
The change, implemented under proposal SIMD-0525, took effect during epoch 1020 on Friday morning. Solana developers plan three further 50ms reductions until the target slot time reaches 200ms. Because each epoch contains 432,000 slots, the shorter slot interval shortens an epoch from roughly 48 hours to about 42 hours. Validators, which are responsible for four consecutive slots per turn, now rotate every 1.4 seconds instead of 1.6 seconds.
The phased rollout was merged into the Anza-developed Agave validator client on May 14. According to Solana Foundation guidance, the upgrade can be paused if too many validators fail to produce blocks in their assigned slots. While shorter slots reduce confirmation and finalization latency for users, they do not automatically increase overall throughput: each slot carries less work, and validators still process the same amount of work over time.
This follows recent capacity improvements on Solana, including a compute limit increase to 100 million compute units adopted on July 29, and the launch of Jump Crypto’s Firedancer client in December, which improved client diversity. Developers are also continuing work on the Alpenglow overhaul, which aims to cut finality from about 12.8 seconds to around 150ms.
The upgrade reinforces Solana’s position as a high-speed Layer 1 network while placing greater operational demands on validators, who must now process block responsibilities more frequently.
