Ethereum Fusaka Upgrade: The Scalability Evolution Behind 12 EIPs

Recently, at the Ethereum execution layer core developers' meeting, the developers reached a consensus on the final scope of the Fusaka upgrade, confirming 12 EIPs including EIP 7939. This marks the official transition of Fusaka from the planning stage to the substantive implementation stage.

As the largest hard fork upgrade since The Merge, the market generally anticipates that if Fusaka is launched as planned by the end of 2025, it will bring significant improvements to L2 data space. This could lead to further reductions in L2 transaction fees within the next 1-2 years, thereby consolidating Ethereum's competitive advantage.

The Continuous Evolution of the Ethereum Scalability Roadmap

The scalability issue of Ethereum has long been the main 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, Ethereum L1 currently has a throughput of 15 transactions per second, and the Gas limit has recently been raised to 36 million, increasing about six times over the past 10 years.

At the same time, Ethereum L2 has made significant progress. Currently, the L2 throughput has reached approximately 250 TPS, achieving a tremendous leap in scalability. This improvement is not only reflected in the data, but many users have also genuinely felt the reduction in costs and acceleration of on-chain operations.

In the past year, the transfer fees of several mainstream L2 networks have generally dropped to around $0.01 or even lower, achieving a significant decrease compared to before. The daily Gas costs on the Ethereum mainnet are also noticeably more user-friendly.

This transformation is not accidental, but rather the result of Ethereum strictly following 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 future upgrades.
• The 2024 Dencun upgrade introduces a Blob data mechanism, providing low-cost temporary storage space for L2 and significantly reducing Rollup costs.
• The recent Pectra upgrade has optimized the validator operation process and enhanced the flexibility of participating in the PoS system.

The upcoming Fusaka upgrade is a crucial step in continuing the aforementioned process.

According to relevant sources, Fusaka plans to launch its mainnet in the third or fourth quarter of 2025, and will implement several core EIPs including PeerDAS data availability sampling, 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 steadily advancing its long-term blueprint - to create a global network that combines security, scalability, decentralization, and sustainability.

Fusaka Upgrade Overview

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

The most notable is EIP-7594 (PeerDAS), which introduces the "Data Availability Sampling (DAS)" mechanism. This allows validators in the network to complete verification by only downloading a portion of the Blob data, without needing to store all the data in full. This significantly reduces the network burden, increases verification efficiency, and lays the foundation for large-scale transaction processing capabilities in L2.

The concept of "Blob" here originates from EIP-4844 introduced in the Dencun upgrade in 2024. As the most significant 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 transactions and transfers on L2.

The core of carrying Blob transactions lies in embedding a large amount of transaction data into the Blob, significantly reducing the storage and processing burden on the Ethereum mainnet. This data is not counted in the mainnet state, directly addressing the L1 cost issues related to data availability, ensuring that L2 platforms can offer more economical and faster transactions without compromising the security and decentralization of Ethereum.

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

Once implemented, the processing capacity (TPS) of L2 is expected to leap to tens of thousands. This will greatly 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. This not only significantly compresses the size of state proofs, making light clients and stateless validation possible, but also helps promote the decentralization of Ethereum and the popularization of mobile terminals.

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

• EIP-7939 (CLZ opcode): Efficient implementation of bit operations to accelerate cryptographic computations.
• EIP-7951 (secp256r1 alternative support): Enhancing compatibility with Web2 and enterprise architectures.
• EIP-7907: Expand contract size limit, support deployment of more complex logic, enhance developer flexibility.

To ensure that scaling does not affect network stability, Fusaka has also introduced EIP-7934 to set block size limits, preventing blocks from becoming too heavy due to Blob expansion, and adjusted Blob usage fees through EIP-7892/EIP-7918 to prevent resource abuse and dynamically match supply and demand fluctuations.

Ethereum Scalability and New Milestones in User Experience

Overall, Fusaka is not only a technological upgrade but also promises to bridge "from scalability to usability" at multiple key levels.

For Rollup developers, this means lower data writing costs and more flexible interaction space. For wallet and infrastructure providers, it means the ability to support more complex interactions and higher-load node environments. End users will experience lower costs and faster responses for on-chain operations. For enterprises and compliant users, EVM scaling and state proof simplification will make on-chain interactions easier to integrate with regulatory systems and for large-scale deployment.

Currently, Fusaka is still undergoing testing on multiple Devnets, and the final launch date may vary. Optimistically, Fusaka is expected to complete its mainnet deployment by the end of 2025, which could become another significant 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. It is expected to provide a solid technical foundation for the next phase of the Rollup ecosystem, enterprise-level Dapps, and on-chain user experience.

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