Monad’s mainnet upgrade makes storing data together 98% cheaper

Monad, an EVM-compatible blockchain, activated its MonadTen revision on mainnet at 14:30 UTC on Sept. 2. The MIP-8 upgrade changes how the network charges contracts for reading storage, replacing slot-by-slot warming with groups of 128 consecutive slots.

Monad’s mainnet block 101672712 measured 8,100 gas to read slot 0, 100 gas to read slot 1 on the same page, and 8,100 gas again at slot 128, the first slot of the next page.

The official MonadTen release record sets activation at Unix timestamp 1788359400. Below that timestamp, MonadNine rules remained in force.

Storage layout now changes the bill

The final MIP-8 specification defines a storage page as 128 words of 32 bytes each, or 4,096 bytes. The first SLOAD anywhere on a page costs 8,100 gas. Later reads anywhere inside that warmed page cost 100 gas for the rest of the transaction, subject to rollback when a call frame reverts.

Under Monad’s prior schedule, two previously untouched slots each cost 8,100 gas even when they sat next to each other. Under the new opcode pricing, the same pair costs 8,100 gas and then 100 gas if both fall within one page.

Common Solidity layouts can inherit that discount automatically. Sequential state variables, struct fields, and array elements occupy consecutive slots, so repeated reads are more likely to stay inside a warmed page.