Analysis of the Ethereum Fusaka Upgrade: The Scaling Evolution Behind 12 EIPs

The Ethereum execution layer core developer meeting was held on June 20, where the final scope of the Fusaka upgrade was determined, including 12 Ethereum Improvement Proposals (EIP). This marks the official transition of Fusaka from the planning phase to the substantive implementation phase.

As the largest hard fork upgrade since The Merge, the market generally expects that if Fusaka is launched as planned by the end of 2025, it will bring significant improvements to the L2 data space. It is anticipated that transaction fees for L2 may further decrease in the next 1-2 years, thereby strengthening Ethereum's competitive advantage.

The Development Logic of Continuous Expansion of Ethereum

The scalability issue of Ethereum has been a core bottleneck for the high on-chain costs of the mainnet and the difficulty in popularizing DApps. According to publicly available data from April this year, the current throughput of Ethereum L1 is 15 transactions per second, and the Gas limit has recently increased to 36 million, which is about a 6-fold increase over the past 10 years.

At the same time, Ethereum L2 has made more significant progress, with the current L2 throughput reaching about 250 TPS, showing clear improvements in scalability. Over the past year, the transfer fees for multiple L2 networks have generally dropped to around $0.01, decreasing by one or even multiple orders of magnitude compared to before. The daily Gas costs on the Ethereum mainnet have also become noticeably more affordable.

This transformation is the result of Ethereum strictly executing its roadmap and continuous iteration. Looking back at the key upgrades of the Ethereum network in recent years:

• The Merge upgrade in 2022 successfully transitioned to the PoS mechanism, significantly reducing energy consumption and freeing up execution layer bandwidth for subsequent upgrades.
• The 2024 Dencun upgrade introduces a Blob data mechanism, providing low-cost temporary storage space for L2, significantly reducing Rollup costs.
• The recent Pectra upgrade optimized the validator operation process and enhanced the flexibility of the PoS system.

The Fusaka upgrade is a key step in continuing this process. According to an executive from the Ethereum Foundation, the Fusaka plan is set to launch the mainnet in the third or fourth quarter of 2025, implementing several core EIPs including PeerDAS, further driving Ethereum to break through performance bottlenecks and move towards mainstream applications.

From The Merge to Dencun, Pectra, and then to Fusaka, Ethereum is systematically advancing towards its long-term goal - to build a global network that combines security, scalability, decentralization, and sustainability.

Fusaka Upgrade Overview

The Fusaka upgrade includes 12 core EIPs, covering multiple technical dimensions such as data availability, node lightweighting, EVM optimization, and the collaborative mechanism between the execution layer and the data layer.

The most notable is EIP-7594(PeerDAS), which introduces the "Data Availability Sampling ( DAS)" mechanism. This mechanism allows network validators to complete verification by only downloading a portion of the Blob data, without the need to store all the data. This greatly reduces the network burden and improves verification efficiency, paving the way for L2 to process transactions on a large scale.

The concept of "Blob" here comes from EIP-4844 introduced in the Dencun upgrade in 2024. As an important milestone for Ethereum in 2024, the Dencun upgrade enabled transactions carrying Blobs for the first time, allowing L2 to choose not to use the traditional calldata storage mechanism, thereby significantly improving the Gas fees for L2 transactions and transfers.

Carrying Blob transactions embeds a large amount of transaction data into the Blob, significantly reducing the storage and processing burden on the Ethereum mainnet, directly addressing the L1 data availability cost issue, and ensuring that L2 platforms provide more economical and faster transactions without compromising the security and decentralization of Ethereum.

The Blob expansion is a further development based on Pectra. The Pectra upgrade in May increased the Blob capacity from 3 to 6. Ideally, Fusaka will expand the Blob capacity to 72 per block (, initially growing to 12-24 per block ). In the future, if DAS is fully realized, the theoretical maximum capacity could reach 512 Blobs per block.

Once implemented, the processing capacity of L2 is expected to soar to tens of thousands TPS, which will significantly enhance the usability and cost structure of high-frequency interaction scenarios such as on-chain DApps, DeFi, social networks, and games.

At the same time, Fusaka also plans to achieve lightweight state and node structure by introducing Verkle trees, which can not only significantly compress the size of state proofs, making light clients and stateless validation possible but also help promote the decentralization of Ethereum and its widespread use on mobile devices.

In addition, Fusaka also focuses on the flexibility and performance bottlenecks of the virtual machine layer (EVM), which includes the following proposals:

• EIP-7939(CLZ opcode): Efficiently implement bit operations to accelerate encryption calculations.
• EIP-7951( secp256r1 replacement support ): Enhancing compatibility with Web2 and enterprise architecture
• EIP-7907: Expand the contract size limit to support the deployment of more complex logic, enhancing developer flexibility.

To ensure that scaling does not affect network stability, Fusaka introduces EIP-7934 to set block size limits, ensuring that blocks do not become too heavy due to Blob expansion. It also adjusts Blob usage fees through EIP-7892/EIP-7918 to prevent resource abuse and dynamically match supply and demand fluctuations.

Ethereum Scalability and Experience Watershed

Overall, Fusaka is not just a technological upgrade; it is expected to lay the foundation for "from scalability to usability" on multiple key levels.

For Rollup developers, this means lower data writing costs and more flexible interaction space; for wallet and infrastructure providers, it means supporting more complex interactions and heavier node environments; for end users, it results in lower experience costs and faster responses for on-chain operations; for enterprises and compliant users, EVM scaling and state proof simplification will also make on-chain interactions easier to integrate with regulatory systems and large-scale deployments.

However, it is still necessary to remain cautiously optimistic. As of now, Fusaka is still undergoing testing on multiple Devnets, and the final launch time may change. Optimistically, Fusaka is expected to complete its mainnet deployment by the end of 2025, at which point it may become another important milestone in Ethereum's history following The Merge.

Overall, Fusaka is not only limited to enhancing on-chain scalability but also represents a key step for Ethereum in transitioning to mainstream commercial applications and ordinary users, promising to provide a technical foundation for the next stage of the Rollup ecosystem, enterprise-level Dapps, and on-chain user experience.

The true watershed for Ethereum's move towards large-scale mainstream applications may be approaching.