Ethereum's Glamsterdam upgrade passes key test ahead of proposed Oct 6 rollout

Ethereum’s upcoming Glamsterdam upgrade cleared a critical rehearsal on the Sepolia public test network, confirming that new block‑building rules work as intended.

Performance test validates new client software

Nethermind, an execution client used by Ethereum nodes, completed a suite of 2,302 performance tests. The client processed 570.7 billion gas in three minutes and 15 seconds, averaging about 2.9 billion gas per second. The benchmark focused on the client’s execution layer rather than the full network.

Block‑level access lists enable parallel processing

The tests exercised block‑level access lists, which inform nodes in advance which accounts and storage slots a block will touch. This advance knowledge allows nodes to fetch data and verify unrelated transactions concurrently, reducing the sequential bottleneck that currently limits block capacity.

Gas limit raised to 200 million for the test

Within an hour of the testnet launch, the block gas limit was increased from 60 million to 200 million. Gas measures the computational work required by transactions, so the higher ceiling creates room for more payments, token swaps and other activity per block.

Potential impact on fees and validators

A 200 million gas limit could absorb higher transaction volumes before users need to outbid each other for block space, potentially softening fee spikes during periods of heavy demand. The upgrade also extends the time validators have to receive and verify block data from roughly two seconds to nine seconds, giving them a larger window to handle bigger blocks.

Next steps

Developers are targeting October 6 for the Glamsterdam deployment on Sepolia, allowing application teams to test their software before the changes reach Ethereum’s main network. The date remains subject to formal confirmation, and the 200 million gas limit is currently a test setting, not a commitment for mainnet.