Solana cuts mainnet slot target to 350ms in first speed step

Solana reduced its mainnet target slot time from 400 milliseconds to 350 milliseconds in the first step of its roadmap toward sub-second speed. The Solana Foundation confirmed the change after the feature gate activated at slot 440,208,000. That slot was the first slot of epoch 1019. The new timing applied when epoch 1020 began on Aug. 21. SIMD-0525 requires a one-epoch delay for the change. Trillium measured a slot-weighted mean of 365.4ms across 431,505 timed slots in epoch 1021. Trillium measured a 420.7ms mean in pre-change epoch 1015. The dataset recorded 331 skipped slots in epoch 1021. That represented 0.077% of slots. The dataset recorded 1,890 skipped slots in epoch 1015. That represented 0.438% of slots. The comparison cannot establish that the timing cut caused the change. Faster slots reduce wall-clock time for confirmation thresholds measured in slots. Four slots remain assigned to each leader. The nominal leader window was 1.6 seconds at 400ms. The nominal leader window is 1.4 seconds at 350ms. The proposal scales per-slot compute, account-write, vote, data, and shred limits down with each shorter target. Blocks arrive more frequently under the change. Each block carries a smaller budget. Approximate work capacity per second remains broadly unchanged. The telemetry reading measures observed spacing between slots. Finality remains a separate metric. Each epoch contains 432,000 slots. The roadmap includes stages at 300ms, 250ms, and eventually 200ms. Each feature gate carries a one-epoch delay so validators can apply the timing and reduced shred limits together. The 300ms stage remained pending as of Aug. 26. Solana Compass reported that Anza CEO and SIMD author Brennan Watt said the stage was intended to become effective at epoch 1024, around Aug. 28. Solana's roadmap says the network can pause between stages if skipped-block rates climb.