What changed in ETH Fusaka upgrade?

TLDR

Ethereums Fusaka upgrade changed how data and fees work: it introduced PeerDAS, raised block gas limits, added secp256r1, capped per?transaction gas, and updated blob fee rules (overview).

1. PeerDAS widened data throughput for rollups by roughly 8, a direct tailwind for lower L2 costs (technical summary).
2. Execution and UX changes: block gas limit to 60M and a new secp256r1 precompile for smoother wallet flows (details).
3. Blob fees now tie to L1 base fees via EIP?7918, restoring a functioning fee market after near?zero blob pricing (fee update).

Deep Dive

1. PeerDAS and L2 Throughput

PeerDAS (data availability sampling) lets validators verify only small samples of blob data, raising rollup data capacity by about 8 and cutting publishing costs for L2s. This is widely viewed as Ethereums first practical step into sharding (technical overview, analysis).

1. PeerDAS reduces node bandwidth while maintaining security, enabling higher throughput without requiring every node to download full blobs (technical overview).
2. Blob capacity can increase incrementally (BPO schedule) to 10/15 and then 14/21 targets, further expanding L2 headroom (analysis).
3. Vitalik Buterin framed this as significant because it literally is sharding, while noting L1 execution parallelization comes later (analysis).

2. Execution and UX Improvements

Fusaka raised the default block gas limit to 60M, introduced a secp256r1 (R1) cryptographic precompile, and added latency?reducing features like pre?confirmations (technical summary).

1. Higher block gas allows more transactions and contract calls per block, reducing congestion in busy periods (technical summary).
2. EIP?7825 caps per?transaction gas (~16.78M) to prevent mega?transactions from monopolizing a block, aiding predictable performance and ZK proving pipelines (deeper dive).
3. The secp256r1 precompile enables modern authentication flows and smoother wallet UX, especially on mobile (technical summary).

3. Blob Fee Market Reform

EIP?7918 ties blob base fees to L1 execution costs, ending the era of near?free blob pricing and restoring a proper fee market for rollup data (fee update).

1. Post?activation, blob fees rose from 1 wei to a functioning level, aligning costs with resource consumption (fee update).
2. The change reduces spam risk, stabilizes sequencer operations, and makes L2 publication costs more predictable (analysis).
3. Some coverage expects blob?driven ETH burn to rise as L2 usage grows, tying data capacity to network incentives (market coverage).

Risk note: A Prysm client bug briefly affected finality and attestations; client diversity kept the network stable while operators applied mitigations (incident report).

Conclusion

Fusaka is a scaling?first upgrade for Ethereum (ETH) that widens L2 data pipes, stabilizes throughput, and normalizes the blob fee market. The immediate impact is lower rollup costs and smoother performance, with longer?term gains arriving as parallelized execution and further sharding features land.