Solana Cuts Mainnet Slot Time to 350 Milliseconds in First Step Toward 200ms Goal
Solana completed a successful mainnet upgrade on Friday morning. The network now targets a slot time of 350 milliseconds, down 50 milliseconds from the previous 400-millisecond target.
A slot is the brief period in which a designated validator produces a block of transactions. This change marks the first step under SIMD-0525, a Solana upgrade proposal merged on May 14. The proposal outlines a path to reduce the target slot time to 200 milliseconds, half its longtime value.
Faster Confirmations and Shorter Epochs
Shorter slots reduce confirmation and finalization latency for users. Any consensus or commitment threshold measured in slots now takes less real-world time.
The change also shortens Solana’s epochs. Each epoch contains 432,000 slots. An epoch that previously took about 48 hours should now take roughly 42 hours. Validators, which control four slots at a time, will rotate every 1.4 seconds instead of 1.6 seconds.
Gradual Path to 200ms Target
Solana developers plan three additional 50-millisecond cuts until the slot time reaches 200 milliseconds. Each stage will activate separately. The rollout can pause if too many validators fail to produce blocks in their assigned slots.
A point-in-time check showed a 1,000-slot period taking 415 seconds before the change. After the upgrade in epoch 1020, the same period took 368 seconds.
Impact on Throughput and Network Design
Shorter slots lower transaction latency but do not automatically increase overall network throughput. Validators handle slots more often, yet each slot carries less work. The change also limits how long one validator can delay or rearrange transactions before the next turn.
Non-voting transactions on Solana have risen notably since the start of the year. These are transactions with a purpose beyond supporting the network itself.
Other Recent Network Improvements
Solana has previously increased the amount of work that fits into each block. In July 2025, developers proposed raising the network’s compute limit to 100 million compute units. That change was merged and adopted on the mainnet on July 29.
The network also added Jump Crypto’s Firedancer client in December. Written in C, it improves client diversity and network resilience alongside the Rust-based Agave client and its popular Jito-Agave fork.
Full finality still takes longer. Solana’s Alpenglow overhaul, still in development, aims to cut finality to about 150 milliseconds from roughly 12.8 seconds today.
