Ethereum validators face a configuration choice before the Glamsterdam upgrade hits the Sepolia testnet on Oct. 6, deciding whether the network tests a scheduled 200 million gas preference or defaults back to 60 million. Two major client teams, Prysm and Teku, ship the upgrade without switching to the higher setting automatically, making validator participation the deciding factor.
A validator choice, not an automatic upgrade
Ethereum's Glamsterdam upgrade is scheduled to activate on the Sepolia testnet on Oct. 6 at 13:53:36 UTC, bringing changes meant to expand the network's execution capacity. Node operators must update both execution and consensus clients before the fork, and stakers must upgrade their beacon node and validator software as well.
But installing compatible software will not by itself push Sepolia toward the 200 million gas preference scheduled for the test. According to the Ethereum Foundation, Prysm 7.2.0 and Teku 26.9.1 both support Glamsterdam but keep a 60 million gas preference after activation unless validators change their settings. Prysm operators must use version 2 proposer settings or the keymanager API, while Teku validators can override the default through their own validator configuration.
Why the gas limit matters for capacity
A higher block gas limit allows more aggregate computation to fit into each block, creating room for more transactions and high-demand applications such as decentralized exchanges and other DeFi protocols. Additional capacity can ease congestion and reduce pressure on transaction fees when demand rises, though it does not make Ethereum's underlying block times faster.
Ethereum has already been moving in that direction: its block gas limit began rising from 30 million toward 36 million in February 2025, the first adjustment since the network moved to proof-of-stake. It then climbed to 45 million before Fusaka client releases adopted 60 million as their default.
200 million is a target, not a guarantee
EIP-8261 introduces an optional gas-limit schedule that lets consensus clients coordinate recommended preferences at specific epochs, but the proposal does not alter Ethereum's consensus-validity rules — blocks stay valid whether their gas limit sits above or below the scheduled value, and validators can choose their own preference instead. That means Sepolia's realized gas limit will move gradually as validators propose blocks, rather than jumping straight to 200 million once Glamsterdam activates.
Glamsterdam combines the Amsterdam execution upgrade with Gloas on the consensus layer and introduces enshrined proposer-builder separation alongside block-level access lists, which let clients parallelize state reads and transaction validation. Ethereum has also added safeguards as capacity rises: Fusaka introduced a 16.7 million gas cap for individual transactions, limiting how much of a block any single operation can consume even as the overall block budget increases.
Sepolia will provide the first scheduled test of Glamsterdam before developers decide how to proceed elsewhere. Hoodi and mainnet activation dates remain undecided, leaving validator participation in the 200 million preference as one of the signals developers will watch before taking the upgrade closer to production.
Source: CryptoSlate
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