Which ETH changes did Fusaka activate?

TLDR

Fusaka activated Ethereums next scaling step by turning on PeerDAS for data sampling, enabling flexible blob-capacity tuning, and bundling protocol tweaks that improve throughput, fees, and validator efficiency.

1. PeerDAS lets validators sample rollup blob data, cutting node load and enabling up to 8x L2 throughput gains as parameters rise, per a network update. Details
2. Blob Parameter Only tuning and fee adjustments allow raising blob capacity without another hard fork and stabilize blob pricing under congestion. Overview
3. Additional EIPs include a higher default block gas limit around 60 million, transaction and block-size caps, proposer transparency, an API for node config, and a new signature type. Summary

Deep Dive

1. PeerDAS Sampling

PeerDAS changes how L2 data is verified by allowing nodes to check small slices of rollup blobs instead of downloading full payloads. This lowers bandwidth and compute requirements and expands blob throughput, laying the foundation for materially cheaper L2 data posting. The activation was on mainnet at block 18,200,000 and is expected to roll out impact gradually as parameters increase for safety. Network details

Fusaka also combined execution and consensus layer changes (often described as Osaka plus Fulu), reflecting synchronized upgrades across Ethereums two layers. Context

2. Blob Tuning and Fees

Fusaka enables Blob Parameter Only changes so client teams can raise blob capacity without a full hard fork and adjusts blob fee mechanics to avoid fee collapse during congestion. This approach helps scale data availability safely while preserving economic incentives for posting data. Mechanics

Developers signaled that increases in blob throughput will be gradual to monitor stability, so the biggest cost reductions arrive over weeks, not minutes. Timeline note

3. Additional Protocol Tweaks

Fusaka packaged a set of EIPs focused on safety, performance, and operations. These include raising the default block gas limit to around 60 million, capping certain transaction and data sizes, aligning blob fees with processing costs, improving block proposer transparency, introducing a node configuration API, efficient contract instructions, and support for a new cryptographic signature type often referenced for passkey-style auth. EIP bundle

The combination aims to make the network more predictable to operate and to sustain a larger validator set while preparing for future scaling work. Broader view

Conclusion

Fusakas core is PeerDAS plus flexible blob scaling, which targets lower L2 data costs and higher throughput without forcing another immediate hard fork. The surrounding EIPs improve safety, capacity, and ops, positioning Ethereum for steady, incremental parameter increases rather than a single switch flip.