Ethereum Glamsterdam: What Parallel Execution and a Higher Gas Limit Mean for the Network

Content type: Deep Dive

Ethereum’s Glamsterdam upgrade is targeting deployment in the first half of 2026, and it represents the most technically ambitious change to Ethereum’s execution layer since the Merge. The market“>upgrade introduces Block Access Lists through EIP-7928, enabling parallel execution of non conflicting transactions across multiple CPU cores, and is expected to increase the gas limit toward 200 collapse“>million per block, a more than threefold increase from the current 60 million. For a network whose stablecoin supply recently crossed $180 billion, bitcoin-2026″>beginners-guide-to-understanding-and-using-cryptocurrency”>understanding what those numbers mean in practice matters.

The Fundamental Problem Glamsterdam Solves

Ethereum currently executes transactions sequentially: one after another, in the order they are included in each block. This is safe and predictable because sequential execution eliminates the possibility that two transactions modifying the same state will produce conflicting outcomes. But it is profoundly inefficient. Modern server hardware has 16, 32, or even 128 CPU cores. Sequential execution uses one core at a time, leaving the vast majority of available computing power idle during every block production cycle.

Layer 2 networks have addressed this throughput constraint by batching Ethereum transactions off the main chain and posting compressed summaries. This is why Ethereum’s $180 billion stablecoin supply can operate without clogging the base layer: most of the transaction volume happens on Arbitrum, Base, Optimism, and other L2s rather than on Ethereum mainnet directly. But L1 throughput still matters for the settlement operations, large trades, and cross protocol interactions that need the security guarantees of the base chain.

How Block Access Lists Enable Parallel Execution

EIP-7928 solves the parallel execution problem through a mechanism called Block Access Lists. Before execution begins, each transaction declares the specific accounts and storage slots it intends to read from or write to. This declaration gives the Ethereum node enough information to determine which transactions are independent of each other: if Transaction A and Transaction B touch completely different parts of state, they cannot conflict and can be executed simultaneously on separate CPU cores.

The mechanism is elegant because it does not require changing the consensus model or the EVM execution semantics. Transactions that conflict with each other, because they both write to the same storage slot, are still executed sequentially. Only genuinely independent transactions are parallelised. The result is a throughput improvement that scales with the degree of transaction independence in a given block, which for most real workloads is high. DeFi activity, stablecoin transfers, and NFT interactions typically involve different protocol contracts and different user accounts. The overlap that forces sequential execution is the exception rather than the rule.

What the Gas Limit Increase Means

The gas limit determines the maximum amount of computational work that can be included in a single Ethereum block. Increasing it from 60 million to 200 million means each block can process roughly 3.3 times more transactions or more computationally intensive operations. Combined with parallel execution, the effective throughput increase is multiplicative: more work per block, and that work happens faster because multiple cores are processing simultaneously.

The gas limit has been deliberately held low to protect node operators. Running an Ethereum full node requires downloading and verifying every block. A very large gas limit means each block can be very large, which increases the hardware requirements for full node operation and can reduce the decentralisation of the network by pricing out lower resource operators. The Glamsterdam approach to this trade off is to increase the gas limit in stages rather than in a single jump, allowing the network to monitor the impact on node operator participation before committing to further increases.

Enshrined Proposer Builder Separation

Alongside parallel execution, Glamsterdam targets the implementation of Enshrined Proposer Builder Separation. Currently, Ethereum’s block production process is dominated by a small number of professional block builders who optimise blocks for maximum extractable value. This concentration creates structural MEV extraction that is economically harmful to ordinary users through worse execution prices and ordering manipulation.

Enshrined PBS separates the role of proposing a block (the validator’s job) from the role of building a block (constructing the optimal transaction ordering). By building this separation into the protocol rather than leaving it as an off chain relay market, Ethereum can establish fairer rules for how blocks are constructed, reducing the advantage of sophisticated MEV extractors relative to ordinary users. The change benefits ETH holders and DeFi participants who currently bear the cost of MEV extraction as an invisible tax on their transactions.

Hegota: The Second 2026 Upgrade

Glamsterdam is the first of two planned Ethereum upgrades in 2026. Hegota, planned for later in the year and combining the Bogota execution layer fork with the Heze consensus layer update, tackles longer range challenges: state bloat (the accumulated growth of Ethereum’s historical state that every full node must store), storage growth, and censorship resistance. While Glamsterdam is primarily about making Ethereum faster, Hegota is primarily about making Ethereum leaner and more resilient.

The two upgrade approach in 2026 reflects the Ethereum Foundation’s updated protocol priorities published in February 2026, which emphasised both near term performance improvement and long term node decentralisation. Running both upgrades in the same year is ambitious and carries execution risk. If Glamsterdam is delayed, it compresses the timeline available for Hegota development and testing.

What This Means for L2s and DeFi

A faster, higher capacity Ethereum L1 does not make L2 networks obsolete. The economics and user experience improvements of L2 transaction fees, which range from $0.001 to $0.10 per transaction, are not replicated at L1 even with the Glamsterdam improvements. What changes is the settlement capacity and cost for L2 networks themselves, which submit proof and data batches to Ethereum L1. A higher gas limit and parallel execution at L1 means L2s can post data more cheaply and frequently, improving finality times and reducing the cost of the on chain security anchor that makes L2s trustworthy.

For DeFi protocols operating directly on Ethereum mainnet, parallel execution means higher transaction throughput during periods of peak demand, reducing the gas spikes that have historically made mainnet interactions economically prohibitive for smaller users during bull market periods.

The TCB View

Glamsterdam is the upgrade Ethereum has needed since the Merge. The Merge addressed consensus efficiency: switching from proof of work to proof of stake reduced Ethereum’s energy consumption by 99.9%. Glamsterdam addresses execution efficiency: using the hardware capacity that modern nodes have available but that sequential execution leaves idle. The combination of parallel execution and a tripled gas limit does not make Ethereum competitive with the fastest L2s on raw transaction cost. But it substantially improves the settlement layer that all of those L2s depend on, and it does so without sacrificing the decentralisation properties that distinguish Ethereum’s security model from faster but more centralised alternatives. Whether Glamsterdam deploys in H1 2026 on schedule will be the first real test of whether the Ethereum Foundation’s updated protocol priorities can be executed at the pace the competitive landscape now requires.