Optimism Speeds Up Subblocks to 200 ms on OP Mainnet

Optimism is rolling out a change to its OP Mainnet that will target 200 ms subblocks, shaving off 50 ms from its current preconfirmation interval. This upgrade is aimed at making the network faster and more efficient by sending incremental updates while a block is still being built.

The four fields in each streamed payload - state_root, block_hash, withdrawals_root, and withdrawals - will remain but carry all-zero values or empty lists, effectively rendering them useless. However, software can continue parsing the stream without errors as the payload type remains ExecutionPayloadFlashblockDeltaV1.

This change is significant because it affects how direct stream consumers treat preconfirmations. Optimism's technical explainer advises treating the zeroed state root and block hash as absent, requiring execution of transactions carried by the stream to derive preconfirmed state.