A Brief Discussion on the Ethereum Gas Limit Controversy: What Are the Pros and Cons of Increasing the Limit for Blocks, Validators, and MEV Earnings?

Author: Seongwan Park

Compiled by: Glendon, Techub News

The Ethereum community has recently focused on a hot topic: increasing the Gas limit. The idea of raising the Gas limit seems reasonable as it aligns with users' demand for higher transaction throughput and reflects the natural growth trend of network capacity over time. Many researchers and community members have expressed strong support for this, believing that Ethereum is well-prepared for this change and viewing it as a timely move to directly enhance Ethereum's scalability.

The proposal has also sparked widespread attention within the community, with community-created websites like pumpthegas.org aimed at popularizing the basics of increasing the Gas limit and how validators can change their node settings. Another site, Gaslimit.pics, actively tracks the progress of validators' support for a higher Gas limit—data shows that as of December 21, 2024, 25% of Ethereum validators have adjusted their client configurations to show support. Once more than 50% of validators agree to raise the Gas limit and modify their client configurations, Ethereum's Gas limit will begin to increase and eventually stabilize at a new target value.

It is worth noting that this proposal differs from Ethereum's rollup-centric roadmap, which contrasts with recent scalability improvements (such as EIP-4844 and EIP-7691) that focus on rollup scaling and blob transactions, while increasing the Gas limit is an L1-level scaling approach (Techub News note: Ethereum block Gas limit refers to the upper limit on the number of operations that can be included in a block, measured by Gas value).

While this discussion excites some community members, it has also raised concerns among researchers about potential risks to Ethereum's core values of decentralization and security. Critics warn that, in the worst-case scenario, larger block sizes could put pressure on the consensus layer and increase hardware requirements for validators, potentially threatening network stability.

Are these concerns unfounded? This article explores the brief history of the proposal to increase Ethereum's Gas limit, its potential impacts, and the technical considerations involved in the ongoing discussions.

Brief History of the Proposal to Increase Ethereum's Gas Limit

In fact, the idea of increasing Ethereum's Gas limit has been discussed for some time. During the Ethereum AMA in January 2024, Ethereum co-founder Vitalik Buterin suggested raising the Gas limit to 40 million (currently, Ethereum's Gas limit is 30 million), which aligns with Moore's Law and reflects the steady improvement in hardware capabilities.

It is noteworthy that Ethereum has not adjusted its Gas limit since April 2021, despite significant advancements in hardware during this period. As a result, many community members now believe it is time for Ethereum to consider these developments.

Recently, a proposal has put forth an "ambitious" goal: to double the Gas limit to 60 million. Of course, 60 million is primarily seen as a long-term goal rather than an immediate target. In December 2024, Toni Wahrstätter suggested a more cautious approach, advocating for an initial increase of the Gas limit to 36 million (a 20% increase) as a safer first step.

Thus, the current increase of Ethereum's Gas limit to 36 million is viewed as an initial milestone, with any further increases following a gradual, phased approach.

How is the Block Gas Limit Adjusted?

The block Gas limit can be gradually increased without the need for a fork or changes to network rules. Instead, validators achieve backward compatibility by modifying their configuration options and making regular, flexible adjustments based on community consensus.

Contrary to popular belief, Ethereum's block Gas limit is not fixed at 30 million. Block proposers can fine-tune it within certain limits. Specifically, the Gas limit of a block can be changed within 1/1024 of the previous block's Gas limit. For example, if the current block's Gas limit is 30 million, it can increase in the next block to "30,000,000 + 30,000,000 × (1 / 1024) = 30,029,296."

The following code demonstrates the default behavior of Ethereum nodes in the geth client: if the Gas limit of the new block is within an acceptable range relative to its parent block, it will be considered valid.

If consecutive block proposers agree to raise the limit, the Gas limit can continue to increase. For instance, in an ideal scenario (assuming validators reach consensus), reaching the first milestone of 36 million (a 20% increase) would take approximately "log(1.2) / log(1025/1024) = 187 blocks," or about 38 minutes. Once more than 50% of validators agree, the increase can be quickly realized.

What Impact Will Increasing the Gas Limit Have?

Let's first look at some relatively predictable impacts of increasing the Gas limit. The increase in block capacity will make it easier to handle current blockchain demands, thereby reducing Gas fees.

In the short term, according to the EIP-1559 mechanism, the reduction in Gas fees may lead to a decrease in the amount of ETH burned, temporarily increasing Ethereum's net issuance. A similar trend was observed after EIP-4844, when the data availability (DA) fees for rollups significantly decreased, leading to a reduction in ETH burned. The increase in the Gas limit may also produce the same effect, further exacerbating short-term inflation.

However, in the long run, the reduction in fees may encourage more network activity, as more users can afford transaction fees. This increased activity could drive Ethereum's network effects, attracting more DApps and promoting broader adoption. As Ethereum becomes an integral part of DApps and DeFi systems, the frequency of ETH's use as a currency may increase. The resulting increase in ETH usage could, in turn, drive further growth in network activity, creating a positive feedback loop for the Ethereum ecosystem.

Building New DApps Will Become Possible After Increasing the Gas Limit

In addition to lowering Gas fees and improving transaction processes, increasing the Gas limit for individual blocks may unlock entirely new opportunities. While a moderate increase to 36 million may not bring significant changes, a more substantial leap to 60 million could enable the creation of new types of DApps and transactions that were previously constrained by the 30 million Gas limit. Certain operations that nearly fill or exceed the current 30 million Gas limit may be executed more efficiently or become feasible for the first time after the change.

For example, transactions that require a large amount of Gas (such as NFT minting in bulk, large-scale token airdrops, or DAO activities) typically approach or exceed the current 30 million Gas limit. These transactions are often spread across multiple blocks, leading to inefficiencies, transaction delays, and potential vulnerabilities. A specific example shown in the figure below is an NFT minting transaction that consumed over 28 million Gas.

Transaction Hash: 0xf99bdd89f7e3186e63d71a4a3ffb53cb5cd1c3190ce3771c966f2a82b3346bee

By increasing the block Gas limit to 60 million, such operations could be completed within a single block, ensuring atomic execution. This guarantees that the entire operation either succeeds or fails, avoiding partial completions, ensuring fairness for participants, and reducing the opportunity for manipulation.

In addition to optimizing existing use cases, a higher Gas limit may also pave the way for innovative DApps that require computationally intensive operations. For instance, with the increase in the Gas limit, on-chain AI applications (such as small-scale model training or inference) may become feasible. Similarly, more complex smart contracts (such as fully on-chain games or intricate governance mechanisms) could thrive in a higher-capacity environment. These advancements could expand Ethereum's functionality and appeal, making the ecosystem more diverse.

Thus, in many cases, doubling the Gas limit may bring more benefits as it can reduce fragmentation and unlock new possibilities.

What Does Increasing the Gas Limit Mean for the Blockchain's "Impossible Triangle" Dilemma?

Increasing the Gas limit fundamentally aims to enhance Ethereum's scalability. In the context of the blockchain's "impossible triangle" dilemma, achieving higher scalability often comes at the expense of decentralization or security. This is why the proposal to raise the Gas limit has sparked some skepticism, with concerns that it may lead to centralization by increasing validator requirements or weaken security by reducing the stability of the consensus layer.

However, supporters argue that this is not about sacrificing decentralization or security for the sake of scalability. Instead, they describe it as leveraging hardware performance improvements described by Moore's Law to expand the total capacity of the blockchain. Under this view, the "triangle" of the blockchain's "impossible triangle" dilemma may expand, as modern hardware allows for greater total capacity without compromising Ethereum's core attributes.

To assess whether this is true, potential risks associated with increasing the Gas limit must be carefully examined. Considerations regarding decentralization may include increased hardware requirements for validators and the complexity of MEV strategies. In terms of security, we should consider the increase in worst-case block sizes and transaction execution times, both of which affect the rates of forks or missed slots.

Increasing the Gas Limit and Block Size

Increasing the Gas limit within a single block accommodates more call data, which affects the worst-case block size. Currently, the maximum block size achievable by filling blocks with meaningless call data is about 1.8MB, while using six blobs, the total data size propagated in a single slot can reach 2.58MB. A higher Gas limit will increase this worst-case block size, potentially causing issues for the peer-to-peer (P2P) layer used for communication among network nodes.

This situation could put pressure on the consensus clients of the P2P layer. When the Gas limit exceeds 40 million, the worst-case block size may surpass the built-in limits in the default client behavior, causing some clients to fail to propose or propagate blocks correctly. Therefore, it is crucial to address these limitations before significantly increasing the Gas limit.

It is hoped that EIP-7623 will provide a solution by adjusting the price of call data in data availability transactions, which could reduce the worst-case block size from 2.58MB to about 1.2MB. Thus, we believe that adopting EIP-7623 will be necessary to ensure that any future increase in the Gas limit maintains consensus stability.

Similarly, the actual block size (the block size typically filled with transaction data) is related to the probability of reorganizing or missing slots. An analysis of slot data (from #9526972 to #10351782) indicates that for smaller blocks, the distribution of block sizes containing slots shows little difference between reorganized/missed slots. However, as blocks grow larger (e.g., exceeding 0.25MB), the likelihood of reorganizing or missing slots increases.

This correlation may stem from factors such as increased transaction execution times or default P2P behavior, rather than block size alone. While the observed relationship highlights potential risks, it does not establish causation.

In summary, while increasing block size may affect slot stability, the worst-case block size is particularly important for ensuring the robustness of the P2P layer. Any future increase in the Gas limit must be accompanied by changes proposed in EIP-7623 to effectively mitigate these risks.

Increasing the Gas Limit and Execution Time

As the increase in the Gas limit allows more transactions to be included in a block, the execution time of transactions will also increase accordingly. Whether this increase is critical depends on the rates of forks or missed slots, which represent the overall stability of consensus.

The following figure shows that as more Gas is used in a block, execution time tends to increase. A 20% increase in the Gas limit is expected to slightly extend execution time, but the specific impact is difficult to predict. Execution time is not always directly proportional to the maximum Gas limit or Gas usage. However, if we make a conservative proportional assumption based on the chart, an increase in execution time of 400 to 500 milliseconds seems reasonable.

Now, let's explore the relationship between execution time and the rates of forks or missed slots.

The red boxes in the figure above emphasize that slots with execution times exceeding 4000 milliseconds are more likely to experience reorganization or missing compared to slots with shorter execution times. While most reorganizations or missed slots occur between 1000 and 3000 milliseconds (indicating a weaker correlation between execution time and reorganization probability within this range), the blocks highlighted in the red boxes show that when execution time exceeds 4000 milliseconds, the likelihood of reorganization significantly increases. Another chart further emphasizes the impact of very high execution times on stability by showing that the reorganization or missing rate of slots with execution times exceeding 4000 milliseconds is more than three times higher than that of slots below 4000 milliseconds.

Will Increasing the Gas Limit Affect Validator Hardware Requirements?

When increasing the Gas limit, validators are primarily concerned about the storage size required to run validator nodes. As of December 2024, a validator node requires about 1.5 to 1.6TB of storage to maintain all historical and state data. The increase in the Gas limit will accelerate the growth of historical and state data.

In 2020 and 2021, running a validator node required a 2TB solid-state drive (SSD). However, when historical and state data reached 1.8TB, validators using 2TB SSDs needed to upgrade to 4TB SSDs. While the price of a 4TB SSD is now roughly the same as that of a 2TB SSD three years ago, at about $250, the upgrade itself entails maintenance costs and technical challenges.

A Gas limit of 36 million may not pose a significant issue. However, if the Gas limit increases to 60 million or more, validator nodes will have to continuously upgrade their hardware, accumulating maintenance costs and threatening decentralization.

When EIP-4444 is adopted (aiming for a client release before May 2025), the growth of historical data may stop, providing more room for increasing the Gas limit. However, without EIP-4444, the growth of historical data may become the next bottleneck for raising the Gas limit.

Storm Slivkoff's analysis of state growth indicates that state growth is also a potential bottleneck, but the current growth rate (approximately 2.62 GiB per month) is manageable, and modern hardware can support ten years of growth. Memory requirements increase with state size, and raising the Gas limit to 60 million will accelerate this process, potentially requiring an additional 2 to 4.7 GiB of RAM per year. While the current configuration of 64 GiB RAM provides sufficient buffer space, ongoing growth may necessitate more frequent upgrades.

Upcoming improvements, such as Verkle trees and state expiry, are expected to alleviate this burden, but careful monitoring remains crucial.

What Does Increasing the Gas Limit Mean for MEV?

Another factor that may impact decentralization is the effect of increasing the Gas limit on validators' MEV (Maximum Extractable Value) earnings. As the importance of MEV becomes more pronounced, concerns have arisen about the income gap between complex validators using advanced MEV strategies and smaller independent stakers. This income gap may exacerbate centralization pressures, as validators with more resources and expertise dominate. To address this issue, the Ethereum community is actively discussing mechanisms such as proposer-builder separation (PBS) and MEV burn, aimed at balancing validator income.

In theory, increasing the Gas limit allows more transactions to be included in a single block, potentially exacerbating the income gap associated with MEV. While MEV Boost has partially mitigated this issue, enabling independent stakers to capture some MEV rewards, data on the income gap among validators remains inconclusive. This is due to challenges in defining MEV transactions and accurately tracking earnings, especially in complex scenarios involving centralized exchanges (CEX) and decentralized exchanges (DEX). However, these scenarios are relatively rare, as most MEV comes from top-of-block strategies.

On the other hand, a higher Gas limit may also enable more complex and resource-intensive MEV strategies. While rare, there are indeed MEV bots executing highly complex transactions that nearly consume the entire block's Gas limit. For example, a bot transaction observed used over 18 million Gas, executing multiple swaps and liquidity operations within a single block. As the Gas limit increases, such strategies may become more common, potentially widening the gap between mature validators and smaller participants.

Conclusion

The discussion surrounding the increase of Ethereum's Gas limit presents an exciting opportunity to drive scalability, reduce transaction fees, and create new possibilities for DApps constrained by current limits. However, this issue also triggers profound concerns regarding decentralization, validator requirements, and network stability. Issues such as the growth of state and historical data, extended execution times, and MEV disparities highlight the necessity for careful consideration and monitoring of empirical data.

Ultimately, the success of raising the Gas limit hinges on how Ethereum skillfully balances these complex factors. Solutions such as EIP-7623, proposer-builder separation (PBS), and MEV burn have already demonstrated the network's proactive attitude toward addressing potential risks, and with careful planning and execution, a higher Gas limit is expected to unlock the next phase of growth for Ethereum.