Ethereum Glamsterdam Upgrade: 200M Gas Target, Parallel Execution, and ePBS Explained

The Ethereum Glamsterdam upgrade, targeted for May or June 2026, represents the most ambitious Layer-1 scaling improvement since the Merge. By combining a 200-million gas target, parallel transaction execution, enshrined proposer-builder separation (ePBS), and expanded data blobs, Glamsterdam addresses the four pillars of Ethereum's scaling challenge: throughput, execution efficiency, block production decentralization, and Layer-2 data availability costs.

This explainer breaks down each component, how they interact, and what the upgrade means for DeFi protocols, L2 ecosystems, and Ethereum's competitive position.

Glamsterdam: Ethereum's Biggest L1 Scaling Upgrade Since the Merge

The Glamsterdam hard fork bundles several critical Ethereum Improvement Proposals into a single coordinated upgrade, targeted for the first half of 2026. The scope is significant: a phased gas limit increase from roughly 60 million to 200 million, true parallel transaction processing, consensus-layer integration of proposer-builder separation, and expanded blob capacity for rollups.

Individually, each feature addresses a specific bottleneck. Together, they deliver an estimated 3x or greater increase in L1 throughput while simultaneously reducing L2 operating costs and mitigating MEV extraction.

The upgrade also lays the foundation for ZK-based validator verification, which Ethereum Foundation researchers view as the key to unlocking even larger capacity increases in future hard forks.

200M Gas Target: From 60M to a New Throughput Ceiling

The gas limit defines how many computations Ethereum can perform per block. The current limit sits at approximately 60 million gas — a figure that has been gradually increased over time but still constrains throughput during high-demand periods.

Glamsterdam implements the increase in two phases. The first phase raises the limit to 100 million gas, roughly doubling current capacity. The second phase, enabled after ePBS deployment, targets 200 million gas — more than three times the current ceiling.

The phased approach reflects the engineering reality that simply increasing the gas limit without corresponding execution improvements would increase hardware requirements for node operators, potentially centralizing the validator set. Parallel execution and ePBS must be operational before the full 200M target is safe to activate.

For DeFi users, a higher gas limit means more transactions per block, reduced congestion during peak periods (token launches, liquidation cascades, governance votes), and lower average gas fees during sustained high-activity windows.

Parallel Execution: Processing Independent Transactions Simultaneously

Today, Ethereum processes every transaction in a block sequentially — one after another, regardless of whether they interact with the same state. This sequential model is safe but inefficient: a simple ETH transfer waits in line behind a complex DeFi swap, even though the two operations touch entirely different accounts and contracts.

Parallel execution changes this. The network will process multiple independent transactions simultaneously, reducing block processing time and enabling higher throughput without proportionally increasing hardware requirements.

The enabling mechanism is EIP-7928: Block-Level Access Lists (BALs). These access lists pre-declare which accounts and smart contracts each transaction within a block will interact with. By knowing in advance which state each transaction touches, the execution engine can identify non-overlapping transactions and run them in parallel without risk of state conflicts.

This pre-declaration also reduces computational overhead for nodes: instead of speculatively executing each transaction and discovering dependencies at runtime, nodes can plan their execution schedule before processing begins. The result is faster block validation and lower hardware demands per unit of throughput.

Parallel execution is foundational for the 200M gas target. Without it, tripling the gas limit would require tripling the time nodes spend processing each block, which would increase block propagation delays and risk consensus instability.

Enshrined Proposer-Builder Separation (ePBS)

Proposer-builder separation (PBS) is the mechanism by which Ethereum separates the role of choosing which transactions go into a block (the builder) from the role of proposing that block to the network (the proposer). Currently, PBS operates through external relays like MEV-Boost — trusted third parties that mediate between builders and proposers.

Enshrined PBS (ePBS) integrates this separation directly into Ethereum's consensus layer, replacing the trusted relay system with a trustless, on-chain mechanism. This eliminates the reliance on centralized relay operators and makes the block production pipeline censorship-resistant by design.

A critical secondary benefit of ePBS extends beyond MEV reform: it provides more time for the generation and propagation of zero-knowledge proofs throughout the network. Ethereum Foundation researcher Justin Drake estimates that approximately 10% of validators will switch to ZK-based verification after ePBS deployment, which in turn enables further gas limit increases beyond the 200M initial target.

This creates a virtuous cycle: ePBS enables ZK adoption, ZK adoption enables higher gas limits, and higher gas limits increase network capacity — all without proportionally increasing hardware requirements for validators.

Expanded Data Blobs: Lower L2 Fees

Glamsterdam continues the blob expansion strategy introduced in the Dencun upgrade (EIP-4844). Data blobs are the dedicated data space that rollups use to post compressed transaction information back to Ethereum L1. The cost of blob space directly affects Layer-2 transaction fees.

More blob capacity helps rollups avoid bidding wars for data availability, which can spike L2 fees during periods when multiple rollups compete for limited blob space. By expanding the number of blobs available per block, Glamsterdam reduces this competitive pressure and provides a more predictable cost structure for L2 operators.

For L2 users, this translates to lower and more stable transaction fees on rollups like Arbitrum, Optimism, Base, and zkSync. For L2 operators, it reduces the operational cost of posting proofs and data to L1, improving the economic viability of the rollup model.

What Glamsterdam Means for DeFi and L2 Ecosystems

The combined effect of Glamsterdam's features reshapes the operating environment for both L1 DeFi protocols and L2 ecosystems.

L1 DeFi protocols benefit from higher throughput and lower congestion-driven fee spikes. Protocols like Uniswap, Aave, and MakerDAO that operate primarily on L1 will see reduced transaction costs during peak demand, improved trade execution, and lower costs for complex multi-step DeFi operations like flash loan arbitrage and vault rebalancing.

L2 rollups benefit from cheaper data posting through expanded blobs and from the reduced L1 congestion that parallel execution provides. When L1 is less congested, L1-L2 bridging transactions also become cheaper and faster.

MEV mitigation through ePBS changes the economics of block production. By enshrining builder-proposer separation, Glamsterdam reduces the ability of individual validators to engage in transaction reordering for profit. This does not eliminate MEV entirely — it remains possible within the builder role — but it removes the trusted relay dependency and creates a more level playing field.

ZK validator adoption may be the most consequential long-term effect. If Drake's estimate of 10% ZK adoption post-ePBS proves accurate, it establishes a baseline for further scaling improvements in subsequent upgrades. Each increase in ZK validator participation enables higher gas limits without increasing hardware burdens.

The Glamsterdam upgrade does not solve Ethereum's scaling challenge in isolation — no single upgrade can. But it represents the most technically ambitious step toward a future where Ethereum L1 can handle significantly higher transaction volumes while reducing costs for both direct users and the L2 ecosystem built on top of it.

Sources

• Ethereum 2026: Glamsterdam and Hegota Forks, L1 Scaling
• Ethereum Glamsterdam Upgrade: The Next Frontier in L1 Efficiency and MEV Reform
• Ethereum sets H1 2026 Glamsterdam plan: ePBS, BALs
• Ethereum 2026 Glamsterdam Upgrade: 200M Gas Target, Blob Expansion, and MEV Fixes
• Ethereum's 2026 Glamsterdam Upgrade: A Strategic Investment Play
• Ethereum's Glamsterdam Upgrade Fork to Undergo Key Upgrades in 2026
• Ethereum 2026: Glamsterdam & Hegota Upgrade