Ethereum Glamsterdam Upgrade Launches on Sepolia with 200M Gas Limit
Ethereum's upcoming major upgrade, Glamsterdam, activated on the Sepolia testnet on October 6 at 13:53 UTC. This marks the final major test before developers decide when to roll out the changes to the main network. The activation followed a last-minute patch from Prysm, a widely used consensus client, which ensures validators propose blocks with a 200 million gas limit instead of the previous default of about 60 million.
The upgrade aims to enhance Ethereum's processing efficiency and scalability. Key changes include separating block proposal and assembly roles and pre-organizing account and storage access information. These modifications are designed to give validators more time to verify transactions and enable concurrent processing, increasing network throughput.
Prysm released version 7.2.1 on October 5 to address a gap left by its predecessor, version 7.2.0 from September 28. The earlier release scheduled the Sepolia fork but did not include the gas-limit change. Validators running the old version would have continued producing blocks at the 60 million gas default, undermining the test's purpose. The new release applies the 200 million gas limit automatically.
The gas limit increase allows for more transactions, stablecoin transfers, and complex applications per block before users compete for block space and fees rise. However, larger blocks demand more hardware resources from validators, which is the focus of the test. The Ethereum Foundation also aims to establish a gas limit floor of 200 million as part of the Glamsterdam upgrade, compared to the current 60 million on the main network.
Sepolia is one of Ethereum's primary testnets, where developers rehearse protocol changes before implementing them on the main network. The Sepolia test will show whether validators can handle blocks more than three times larger than the previous default. Glamsterdam has not yet been scheduled for the mainnet, and developers will use the test results to determine the main network's capacity expansion.
Beyond the gas-limit change, the Prysm patch also turns on partial data columns by default and reworks builder configurations in the validator client. These changes aim to evaluate how far block space costs can be pushed down without compromising network stability. Client diversity remains a core safety feature of Ethereum, and the last-minute patch highlights the importance of testnets in identifying and resolving issues before they reach the main network.