From BPO parameters to ten-thousand TPS: How Fusaka upgrade reshapes Ethereum scaling solutions

December 3, 2025, the Ethereum mainnet will undergo a groundbreaking upgrade—Fusaka. This is not only the second major hard fork following the Pectra upgrade in May but also marks a critical turning point for Ethereum’s move toward modularity and efficient scalability. The Fusaka upgrade is composed of two core technical codenames: Osaka, representing execution layer optimization, and Fulu, corresponding to consensus layer improvements. To understand the true significance of this upgrade, one must first grasp a crucial concept—BPO.

The Core Engine of the Fusaka Upgrade: Understanding BPO and PeerDAS

Rollups have become the primary vehicle for Ethereum’s throughput, but their growth is constrained by L1 data availability and costs. The birth of the Fusaka upgrade aims to break this bottleneck. The key innovation is PeerDAS technology—peer data availability sampling—under the EIP-7594 specification.

Unlike traditional methods requiring each full node to download all data blocks, PeerDAS employs an innovative segmentation and sampling mechanism, dividing data into smaller fragments. Validating nodes only need to obtain random samples to ensure the complete data exists. This approach significantly reduces bandwidth and storage pressures on nodes while laying a solid foundation for data capacity expansion.

But what truly enables this system to operate flexibly is BPO—“Blob-Only Parameter” mode. What is BPO? In short, it is a lightweight hard fork mechanism that allows Ethereum to adjust three key parameters—Blob capacity target, Blob capacity upper limit, and base fee adjustment factor—without large-scale upgrades. This innovation changes the traditional upgrade rhythm—once requiring years for major forks, now enabling smaller, more frequent updates.

EIP-7892 officially introduces the BPO fork mechanism. This means that as L2 applications grow and demand more data capacity, Ethereum can respond quickly by implementing BPO forks to achieve gradual capacity increases. Analysts estimate that Fusaka combined with the first BPO fork could reduce L2 data costs by 40% to 60% over an extended period.

Flexible Scalability: How BPO Forks Change the Upgrade Pace

Traditional Ethereum upgrades often require significant resources across development, testing, and deployment stages. The emergence of BPO forks reshapes this landscape.

To enable this flexibility, Fusaka also synchronously adjusts execution layer parameters. EIPs-7825 and 7934 specify transaction layer gas limits, while increasing the RLP block size limit to 10MB, accommodating more data and effectively preventing denial-of-service attacks. EIPs-7823 and 7883 reprice and restrict cryptographic precompiles to ensure complex cryptographic computations do not stall block processing.

The core logic of these parameter adjustments is to leave more space for Rollups while ensuring protocol security. Unlike traditional upgrades, BPO forks allow Ethereum to respond more nimbly to increasing data demands.

Practical Application of Ethereum’s Long-Term Roadmap: From Merge to Modular

To understand Fusaka’s position in Ethereum’s development, it’s essential to review recent major upgrade milestones.

In 2022, The Merge transitioned Ethereum from proof-of-work to proof-of-stake, reducing energy consumption by 99.9%. Subsequently, the Shapella upgrade (2023) enabled withdrawal of staked ETH, fostering liquid staking. The Dencun upgrade in March 2024 introduced EIP-4844 “Blob” technology, providing a cheaper temporary data channel for Rollups. In May of the same year, the Pectra upgrade added EIP-7702 account abstraction, optimizing staking mechanisms.

These upgrades align with Vitalik Buterin’s long-term roadmap framework: Merge, Surge, Verge, Purge, and Splurge. Surge focuses on scalability via Rollups and data availability solutions; Verge and Purge aim to build lighter clients and clean historical data.

Fusaka’s uniqueness lies in its ability to simultaneously advance multiple roadmap goals. As a representative of Surge, it paves the way for Rollup data scalability through PeerDAS and BPO; as an implementation of Verge and Purge, it optimizes historical data management and lightweight synchronization mechanisms. More importantly, Fusaka sets clear targets for a modular Ethereum stack—building on L1 settlement to support over 100,000 transactions per second (TPS) via L2.

Comprehensive Upgrades in User Experience and Security

Fusaka is not just about data scalability; it also enhances user experience and developer tools.

EIP-7917 establishes the proposer schedule for the next epoch, accessible on-chain via the beacon root. This is crucial for applications relying on Rollups and pre-confirmation schemes, as they need to pre-know validator identities to provide reliable soft finality guarantees.

At the user level, EIP-7951 adds support for secp256r1 precompiles, making Ethereum natively compatible with the P-256 signature curve. This curve is widely used in Apple’s Secure Enclave, Android Keystore, FIDO2, and WebAuthn. It means wallets can rely on device-level biometrics instead of mnemonics, bringing L1 login experiences closer to mainstream app convenience.

For developers, EIP-7939 introduces an operation code for counting leading zeros, reducing costs for bit-level operations, big integer processing, and zero-knowledge proof circuits. Meanwhile, EIP-7642 extends the historical data expiration mechanism, allowing nodes to safely discard pre-merge data, saving hundreds of GB of storage per node, and significantly speeding up synchronization for new validators.

Multi-Dimensional Benefits: L2, Validators, Users All Win

The impact of Fusaka extends across various participants in the Ethereum ecosystem.

For the L2 ecosystem, the combination of PeerDAS and BPO forks creates an environment with ample data and lower costs. Cost reductions are expected to trigger a new wave of competition among Rollups focused on DeFi, gaming, social, and other high-throughput applications, driving innovation.

For node operators and validators, the situation is more complex. Data sampling and historical expiration mechanisms reduce download and storage burdens, lowering the barrier for new validators. However, as BPO forks increase Blob capacity, well-equipped validators will need to handle higher uplink bandwidth. If client implementations are inadequate, this could lead to network centralization around larger operators.

For institutions and staking service providers, Fusaka’s value lies in predictability. Clearer data throughput, safer gas and block parameters, and more transparent historical data management provide a better foundation for large-scale validator operations.

For ETH holders, the impact is both tangible and profound. Ethereum is being tuned into a high-capacity settlement engine focused on L2. Adjustments to minimum fees and Blob pricing attract more transactions to settle on L1, reshaping fee markets and validator rewards. However, this evolution also carries risks—protocol complexity increases, and if ordinary users do not perceive significant cost or experience improvements, controversy may arise.

Moving to the Next Stage: Glamsterdam and the Distant Future

Fusaka is not the end but a stepping stone toward the next phase. The expected Glamsterdam upgrade in 2026 will introduce two key innovations: proposer builder separation (ePBS) and block-level access lists (BAL).

ePBS aims to separate block construction and proposal functions at the protocol level, enhancing MEV transparency. BAL will optimize execution efficiency and state access, preparing for further Blob capacity increases.

From a macro perspective, Fusaka signifies an evolution of Ethereum’s roadmap from fragmented planning to a coherent vision. PeerDAS and BPO forks advance Surge’s data scalability goals; historical expiration and P2P optimizations reflect Verge and Purge’s lightweight aspirations; proposer previews and P-256 support clear the way for widespread pre-confirmation and key-wallet applications.

If Ethereum maintains this upgrade pace and strategic focus, Fusaka’s significance will go beyond technical optimization—it will become a turning point for the ecosystem’s move toward modularity, efficiency, and security. Its ultimate goal—to support a modular stack capable of 100,000 transactions per second while maintaining decentralization—is gradually transforming from vision to reality.