Ethereum developers are preparing to test a significant expansion of Layer 1 execution capacity as the Glamsterdam upgrade approaches activation on the Sepolia testnet on Oct. 6 at 13:53:36 UTC. Node operators and stakers—who recently observed infrastructure shifts such as MetaMask exiting Ethereum staking validators—must update their execution, consensus, beacon node, and validator software prior to the fork.
Client Configuration and EIP-8261 Mechanics
Installing compatible software will not automatically push Sepolia to the target 200 million gas limit. Client releases such as Prysm 7.2.0 and Teku 26.9.1 support Glamsterdam but will retain their 60 million gas preference by default after activation. Prysm validators must manually adjust settings via version 2 proposer configurations or the keymanager API, while Teku operators must override defaults through their validator setup.
This gradual transition is governed by EIP-8261, which introduces an optional gas-limit schedule allowing consensus clients to coordinate recommended preferences at specific epochs. EIP-8261 does not alter consensus-validity rules, meaning blocks remain valid whether their gas limit sits above or below the target value.
Ethereum's gas capacity has grown systematically over time. The block gas limit increased from 30 million toward 36 million in February 2025 in the first adjustment since moving to proof-of-stake, subsequently climbing to 45 million before Fusaka client releases set the default at 60 million.
Architecture Upgrades and Network Safeguards
Glamsterdam combines the Amsterdam execution upgrade with Gloas on the consensus layer. The combined upgrade introduces enshrined proposer-builder separation alongside block-level access lists, enabling client software to parallelize state reads and transaction validation.
- Sepolia activates Glamsterdam on Oct. 6 at 13:53:36 UTC to evaluate a 200 million gas limit.
- Prysm 7.2.0 and Teku 26.9.1 retain a 60 million default gas limit unless node operators explicitly update configuration settings.
- EIP-8261 coordinates epoch gas preferences without modifying underlying protocol consensus rules.
- Individual transaction gas consumption remains capped at 16.7 million under limits introduced during Fusaka.
To manage risk as total block capacity increases, Fusaka established a 16.7 million gas cap for individual transactions. This ensures higher block limits provide aggregate room for protocols like decentralized exchanges rather than allowing single smart-contract execution to consume entire blocks. Deployment schedules for the Hoodi testnet and Ethereum mainnet remain undecided.
Why It Matters
The Glamsterdam trial on Sepolia is a crucial test of whether Ethereum can scale its execution layer directly alongside Layer 2 networks. By testing a 200 million gas preference combined with parallel state reads and enshrined proposer-builder separation, developers are testing if nodes can process higher transaction volume without suffering performance degradation or state growth issues. The reliance on manual validator configurations will also test decentralized node operator coordination before developers move the upgrade toward mainnet deployment.
