Solana to Cut Slot Time to 350 Milliseconds at Epoch 1020

Solana will shorten its slot time to 350 milliseconds at Epoch 1020, down from the current roughly 400 milliseconds, according to Solana core developer and Anza CEO Brennan Watt. Watt said the network is now activating its first slot-time reduction on mainnet. The change is expected to take effect at Epoch 1020. He also warned developers that the upgrade comes with a transition period. Some SDK constants, including DEFAULT_MS_PER_SLOT, have not yet been updated to the new parameter, and the official team will release a version with the latest numbers after the feature is activated. The rollout uses delayed activation. In Watt’s description, the feature enters a pending state at Epoch E, activates at Epoch E+1, and becomes fully effective at Epoch E+2. For applications that depend on SDK constants staying aligned with mainnet slot timing, Watt recommended adding extra compatibility logic during the transition. One example is to set feature-switching rules around Epoch slot boundaries so services do not break when timing parameters change. Watt said Solana eventually wants to move these network parameters on-chain so clients can query them directly. Before that happens, though, the team needs to finish this upgrade first. He described the process as similar to Solana’s early phase of "difficult but fast iteration." Watt also said the team expects most nodes to reach a two-slot delay target in most situations, and that those limits will be relaxed further in Anza v4.3.