Monad Mainnet Upgrade Cuts Data Storage Costs by Up to 98%

Monad, an Ethereum Virtual Machine (EVM)-compatible blockchain, has successfully activated its MonadTen revision on mainnet. This upgrade, which took place at 14:30 UTC on September 2, is expected to make storing data together significantly cheaper. The MIP-8 upgrade changes how the network charges contracts for reading storage, replacing slot-by-slot warming with groups of 128 consecutive slots.

Before the upgrade, reading a single slot cost 8,100 gas, while reading multiple slots next to each other still incurred this high gas cost. However, under the new opcode pricing, the first SLOAD on a page costs 8,100 gas, but subsequent reads within the same warmed page cost only 100 gas.

This change is expected to make a significant impact on developers who store data in close proximity, as it can reduce their costs by up to 98%. Common Solidity layouts can now inherit this discount automatically. Sequential state variables and array elements that occupy consecutive slots are more likely to stay within the same warmed page.

However, it's worth noting that reads that cross page boundaries still cost 8,100 gas each, and savings depend on how many slots a transaction touches and whether those slots cluster within the same 128-slot boundary. The upgrade also preserves EVM execution semantics while changing the assumptions used by tooling that builds access lists, storage proofs, or gas estimates.