Solana is activating its first mainnet upgrade to shorten slot time, a change that is expected to reduce block production time from about 400 milliseconds to 350 milliseconds, according to Brennan Watt, a core Solana developer and CEO of Anza. The adjustment is set to formally take effect starting in Epoch 1020.
Epoch 1020 marks the start of the change
Watt said this will be the first slot-time reduction upgrade on Solana mainnet. Once in place, the network’s block production interval is expected to move down from roughly 400 ms to 350 ms.
Developers are being warned about transition issues
Watt said the upgrade comes with transition-stage complications for developers. Some SDK constants, including DEFAULT_MS_PER_SLOT, have not yet been synchronized with the new parameter. The official update carrying the revised values will be released after feature activation.
He advised teams whose applications depend on SDK constants matching actual mainnet slot timing to add compatibility handling during the transition period. One example he gave was using epoch slot boundaries as switching points for feature logic, so services do not break when timing parameters change.
The rollout uses delayed activation
Watt said the feature follows a delayed activation model rather than becoming fully active at once. Under that process, the feature enters a pending-activation state in Epoch E, activates in Epoch E+1, and only becomes fully effective in Epoch E+2.
Long-term plan is to move parameters on-chain
Over a longer horizon, Watt said Solana plans to migrate these network parameters on-chain, allowing clients to query them directly. For now, he said, the team needs to complete this upgrade first. He described the process as similar to Solana’s early period of 「difficult but fast iteration」.
Watt also said the team expects the vast majority of nodes to reach the target of 「two-slot latency」 in the vast majority of cases. Related limits are expected to be relaxed further in Anza v4.3.