Solana halves its block time to 200ms, doubling block opportunities without doubling capacity

Solana/Solana mainnet & Firedancer

Solana's SIMD-0525 upgrade took effect on mainnet on October 9, 2026, cutting the target slot time from 400ms to 200ms. Blocks now come twice as often, but the compute budget per slot was cut in step, so overall execution capacity per second is roughly unchanged.

• The change rolled out in four stages from August (350ms, 300ms, 250ms, then 200ms); an epoch now takes about 24 hours instead of 48.
• Blockhash expiry drops from about 60 seconds to about 30, leaving apps that sign offline or submit late less time.
• CryptoSlate's sampling of one public mainnet RPC found an average of about 222ms across 1,413 slots and says the network has not yet consistently hit the new target.
• Alpenglow, a separate consensus overhaul targeting about 150ms finality, is running on testnet and devnet; no mainnet activation date has been announced.