Ethereum Activates Fusaka Upgrade on Sepolia Testnet, Testing High Gas Blocks & PeerDAS

Market Context

Ethereum is in the midst of an infrastructural evolution as it seeks to scale more efficiently, especially with Layer-2 adoption surging. The success of Fusaka—and its data availability innovations like PeerDAS—is considered pivotal for reducing costs and improving throughput on Ethereum’s base layer, which in turn impacts how competitive it is relative to high-throughput chains.

Technical Details with Attribution

• Upgrade Phase: The Sepolia activation is the second of three major testnet deployments, following Holesky (activated Oct 1) and preceding Hoodi (set for Oct 28). 
• Gas Limit & Throughput: The testnet is now operating with a 60 million gas block limit, allowing more transactions and complex smart contract execution per block. 
• PeerDAS Implementation: PeerDAS enables validators to sample portions of data from peers instead of downloading entire blobs, reducing node burden while securing data availability. 
• Node Considerations: Developers have emphasized that existing client setups (hardware, network) must reliably handle 60M gas blocks without destabilizing performance.
• Roadmap Timing: After Sepolia testing, the final testnet activation (Hoodi) is scheduled for October 28, with a target mainnet launch date of December 3, 2025. 

Analyst Perspectives 

Many in the Ethereum community regard the Sepolia upgrade as an important litmus test. If the network remains stable under high gas usage with PeerDAS, it could validate the design for mainnet. But some remain cautious: real-world stress, edge cases, and interoperability with Layer-2s may expose unforeseen issues. The final verdict will depend on how well the transition preserves decentralization and node viability under increased demands.

Global Impact Note

If Fusaka executes smoothly on mainnet, Ethereum would significantly strengthen its infrastructure and scalability posture—potentially attracting more developers and capital from competing chains. The rollout may also set benchmarks for data availability systems across blockchains worldwide.