Ethereum’s Glamsterdam Rehearsal Clears a 200 Million Gas Test

Ethereum’s next major upgrade just moved through a meaningful rehearsal without losing the plot.

Glamsterdam’s Devnet-11 continued producing blocks after switching to its new block-building rules. Nethermind separately completed a large performance test for one of the upgrade’s core execution changes.

The result does not mean the upgrade is ready for mainnet. It does show that two of its most important ideas are working under controlled conditions.

CoinDesk says the test network raised its block gas limit from 60 million to 200 million about an hour after launch. That higher ceiling gives each block room for more transfers, swaps and smart-contract activity.

The publication also reports that Nethermind completed all 2,302 tests in its benchmark while processing 570.7 billion gas in three minutes and 15 seconds. The average came to roughly 2.9 billion gas per second.

That figure describes one client benchmark, not the speed Ethereum users should expect from the live network. Developers have not committed to putting the same 200 million setting on mainnet.

The distinction matters because larger blocks create more work for node operators. If smaller operators cannot receive and validate them in time, a capacity increase could weaken decentralization even while it creates more room for transactions.

Glamsterdam tries to solve that tension with architectural changes instead of relying on brute force. The test is evidence that the approach can work, but it is not a final verdict on production readiness.

The public EthPandaOps specification describes a six-consensus-client by seven-execution-client matrix with 84,000 validators. It also records a scheduled increase from 60 million to 200 million gas after the fork transition.

Devnet-11 was designed as a happy-path rehearsal for client teams and major Layer 2 builders. Deliberate attack testing remains on a separate network, so the clean transition is one checkpoint in a larger testing process.

The proposed Sepolia timetable was still conditional on September 10, with Devnet-11 identified as the next test that had to work:

It's been about a week since this post went out to my Substack subscribers, and the caveats about the Oct 6 Sepolia testnet upgrade date still hold.

The only minor update now is that all eyes are on the launch of Glam-Devnet-11 next Monday, not Devnet-10. https://t.co/WIhwYhAHoy

— Christine D. Kim (@christine_dkim) September 10, 2026

The most interesting performance result came from block-level access lists, or BALs. They tell an Ethereum client which accounts and storage slots a block will touch before transaction execution begins.

That advance notice allows clients to fetch data earlier and process unrelated work in parallel. Ethereum has traditionally executed much of a block in sequence, which limits how much activity it can safely fit into each block.

If clients can prepare and process independent state changes at the same time, the network has a path to larger blocks without demanding proportionally larger machines from every operator. That is the practical promise behind the benchmark.

Glamsterdam also changes how block builders and validators coordinate. More of that relationship would move into Ethereum’s protocol rules, reducing reliance on outside relay infrastructure and giving block data more time to move across the network.

A related Gloas change keeps Merkle proofs compatible across future hard forks. That plumbing matters to protocols that depend on beacon-chain data:

Another Gloas EIP, forward compatible consensus data structures has recently been merged.

Thanks to this EIP, merkle proofs generated from consensus data (e.g. the Beacon State) will be compatible across future hard forks. This is great for protocols who rely on beacon chain…

— Sigma Prime (@sigp_io) September 11, 2026

Developers are targeting October 6 for a Glamsterdam deployment on Sepolia, Ethereum’s public test network. The date remained conditional before Devnet-11 because the upgrade still needed another stable private-network transition.

The test plan had already moved through several devnet iterations as teams worked through execution and consensus bugs. Sepolia is therefore a milestone, not a ceremonial date that automatically leads to mainnet.

The Ethereum All Core Devs testing record shows the client-readiness work behind that caution. Teams were reviewing specification versions, client behavior and known failure cases before Devnet-11 launched.

If Sepolia proceeds and stays stable, application developers will get a more realistic environment for testing wallets, contracts and infrastructure against the new rules. Hoodi and mainnet would come later, after developers have evidence that the changes hold up outside a controlled rehearsal.

Glamsterdam has now survived an important transition, and a leading execution client has posted a strong BAL benchmark. The next proof comes on a public testnet, where more software and more users can test whether Ethereum’s capacity plan holds together.

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