Solana has reduced its target slot time from 300 milliseconds to 250 milliseconds, effective September 18, 2026, with the start of epoch 1037. This change increases block production to four slots per second, compared to the previous rate of approximately 3.3 slots per second.
The update represents the fourth stage of the SIMD-0525 proposal. While the network clock is faster, transaction throughput remains unchanged. To maintain stability, Solana reduced maximum compute units per slot from 60 million to 37.5 million and adjusted data shred limits accordingly.
The primary goal of this adjustment is to improve data freshness for trading applications and wallets. Additionally, the duration of an epoch has decreased from approximately 36 hours to about 30 hours, impacting staking rewards and validator operations.
Leader control windows have been reduced from 1.2 seconds to 1 second, limiting the time validators have to broadcast blocks. Developers aim for a final target of 200 milliseconds per slot, pending further testing of block-skip rates on the mainnet.
