Solana to activate first mainnet slot-time reduction, cutting interval to 350 ms
Solana is preparing to activate its first mainnet upgrade to shorten slot time, according to Brennan Watt, a core Solana developer and CEO of Anza. The change is expected to reduce block production time from about 400 milliseconds to 350 milliseconds, with formal effect beginning at Epoch 1020. Watt said developers should watch for transition issues because some SDK constants, including DEFAULT_MS_PER_SLOT, have not yet been updated to reflect the new setting. An official release with the revised values will be published after the feature is activated. He also said the rollout uses a delayed activation model: the feature enters a pending state in Epoch E, activates in Epoch E+1, and only becomes fully effective in Epoch E+2. Applications that rely on SDK constants matching actual mainnet slot timing may need extra compatibility logic during the transition, such as switching behavior at epoch slot boundaries. Over the longer term, Watt said Solana plans to move these network parameters on-chain so clients can query them directly. He added that most nodes are expected to hit the target of a two-slot delay in most cases, and related limits are set to be loosened further in Anza v4.3.








