Solana is about to halve its block times as final 200-millisecond upgrade nears

Solana is preparing to cut the time between blocks to 200 milliseconds on Friday, completing a series of upgrades that has halved the network’s target block production time since August.

The final reduction, from 250 milliseconds, is scheduled to take effect at epoch 1053, expected around 15:00 UTC, according to Anza, the developer of Solana’s widely used Agave validator software.

The change would allow the blockchain to target five block-production opportunities every second, compared with 2.5 under the original 400-millisecond configuration.

A slot is the short window in which a designated validator can add transactions to the blockchain. Shorter slots mean trading applications, wallets and exchanges can receive updated information more frequently, reducing the time a submitted transaction may spend waiting to be processed.

The changes began Aug. 21, when Solana moved to 350 milliseconds, followed by reductions to 300 milliseconds on Aug. 28 and 250 milliseconds on Sept. 18.

The technical proposal, known as SIMD-0525, also limits how much computing work validators can pack into each block.

At 200 milliseconds, each block can carry a maximum of 30 million compute units, down from 37.5 million at 250 milliseconds. Blocks arrive more frequently, but each carries proportionally less work, keeping the network’s theoretical processing capacity roughly unchanged.

Read More: Solana transactions just got more than 3 times bigger, narrowing the gap with Ethereum

Validators will continue producing blocks in groups of four consecutive slots. Their uninterrupted window to order transactions will consequently shrink from 1.6 seconds under the original configuration to 800 milliseconds.

That could reduce opportunities to delay transactions or exploit prices that have moved on other exchanges before Solana catches up.

The faster clock also comes with costs. Validators that submit votes on every slot will need to do so about twice as frequently as under the original configuration, increasing voting expenses and placing greater pressure on network connections.

Wallets and other applications also have less time to use a recent blockhash, a reference included in transactions to prevent them from being replayed. The shorter validity window could complicate transactions requiring manual approval or offline signatures.

Solana Compass data shows the previous 250-millisecond configuration delivered average slot times of approximately 266 to 269 milliseconds across recent epochs, slightly slower than its target.

The final reduction has already been deployed on Solana’s testnet and devnet. Developers have said the mainnet rollout depends on network conditions, particularly the rate at which validators miss their assigned block-production opportunities.

The transition is expected to occur at the epoch 1053 boundary on Friday.