Ethereum's Glamsterdam Hard Fork: The Most Significant Overhaul Since The Merge

Ethereum is on the verge of its most radical architectural evolution since 2022's historic transition to Proof-of-Stake. Dubbed Glamsterdam—a combination of the execution layer "Amsterdam" and the consensus layer "Gloas"—this massive hard fork has officially entered its final devnet testing phases.

With public testnets looming, developers are targeting a mainnet release. Unlike previous upgrades that focused on scaling Layer 2 rollups, Glamsterdam is built to scale Layer 1 directly, aiming to handle over 10,000 transactions per second (TPS) and cut base-layer fees by up to 78%.

Here is a breakdown of the three key pillars driving this landmark upgrade.

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1. Trustless MEV: Enshrined Proposer-Builder Separation (ePBS)

At the heart of Glamsterdam is EIP-7732, which introduces Enshrined Proposer-Builder Separation (ePBS). Currently, over 90% of Ethereum blocks are constructed using MEV-Boost, an off-chain framework that relies on centralized, trusted intermediaries called "relays" to deliver block payloads to validators.

ePBS moves this entire marketplace directly into the Ethereum protocol, completely eliminating the need for trusted relays. By splitting the block into two distinct parts—the consensus block and the execution payload—validators no longer have to process heavy EVM state transitions in a frantic four-second window. Instead, validators handle consensus, while builders bid and post cryptoeconomic bonds to assemble the transactions. A randomly designated Payload Timeliness Committee (PTC) of 512 validators checks whether builders deliver payloads on time, safely expanding the block execution window.

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2. Parallel EVM: Block-Level Access Lists (BALs)

To turn Ethereum into a high-throughput engine, Glamsterdam is introducing EIP-7928, also known as Block-Level Access Lists (BALs).

Historically, EVM transactions had to be executed sequentially because the network couldn't predict which accounts or storage slots would be accessed in advance. EIP-7928 solves this by requiring blocks to pre-declare a map of all storage interactions and state changes. Armed with this map, validators can identify non-conflicting transactions and execute them in parallel across multiple CPU cores. This parallelization allows developers to confidently raise the block gas limit from 60 million to 200 million, laying the groundwork for high-performance decentralized applications.

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3. Mass Gas Repricing and L2 Relief

Beyond structural performance, Glamsterdam delivers direct financial relief to users through EIP-7904, a comprehensive gas repricing package. By restructuring how data storage is charged, the upgrade is projected to slash L1 fees for simple native transfers by roughly 78.6%.

Furthermore, this abundance of cheaper, parallelized L1 block space will trickle down to Layer 2 rollups. It will dramatically lower the costs rollups pay to settle transactions on the base chain, making Web3 gaming, micro-payments, and decentralized finance more accessible than ever.

As Glamsterdam transitions from developer environments to public testnets, the Ethereum network is proving that L1 decentralization does not have to come at the expense of speed and affordability.