Ethereum’s Fusaka Upgrade: 60M Gas Blocks & Paving the Road to Parallel Execution

Title: Ethereum’s Fusaka Upgrade: 60M Gas Blocks & Paving the Road to Parallel Execution

Introduction Ethereum’s growth has been hampered by network congestion and soaring gas fees, affecting usability for developers, investors, and end-users alike. The Fusaka upgrade, arriving on mainnet December 3, promises to ease these pain points by raising the block gas limit from 45 million to 60 million (a 33% boost), introducing Peer Data Availability Sampling (PeerDAS), and establishing the foundations for parallel execution and danksharding. In this post, we’ll explore each enhancement in depth, examine how Layer-2s will leverage them, assess MEV implications, and outline critical developer action items. Let’s begin with the most immediate change: more gas per block.

1. Raising the Gas Limit to 60 Million: More Transactions, Lower Fees With EIP-7935, Fusaka lifts the default block gas limit to 60 million units, expanding L1 capacity by 33% under controlled parameters. After rigorous devnet and testnet stress tests— where blocks processed full loads without consensus or health issues— core developers approved the bump during September’s All Core Devs call. Economically, this capacity increase should translate into lower per-unit gas prices when demand remains steady, benefiting users and L2 rollups posting data on L1. Previous upgrades (to 36 M in February and 45 M in July) yielded immediate fee relief during moderate traffic. By enabling more transactions per block, Fusaka aims to reduce peak congestion costs and dampen gas-price volatility.

Transitioning from boosting raw capacity, Fusaka also revolutionizes how nodes verify rollup data availability.

2. PeerDAS & Data Availability: Scaling for Layer-2s Under EIP-7594, PeerDAS allows nodes to sample randomized portions of Layer-2 blob data and use KZG commitments to verify full availability. As Vitalik Buterin notes, no node needs to download entire blobs— drastically cutting bandwidth and storage demands while preserving security and decentralization. In practice, empirical savings (estimated at 30–50%) await validation on mainnet. Fusaka’s Blob Parameter Only forks let rollups scale blob counts from six to 10, then 14 per block, without overburdening validators or light clients.

With higher gas limits and efficient data sampling in place, Fusaka readies Ethereum for true parallel execution.

3. Paving the Way for Parallel Execution and Danksharding EIP-7825 imposes a 2^24 (≈16.78 million) per-transaction gas cap, preventing single mega-transactions from monopolizing a 60 M block. This constraint smooths block packing, a prerequisite for upcoming multi-threaded EVM pipelines. Fusaka also raises the RLP block-size cap to 10 MiB (with a 2 MiB safety margin), aligning gossip limits with larger blob payloads and curbing DoS risks. These adjustments optimize block construction for the asynchronous, parallel execution architectures envisioned in Ethereum’s danksharding roadmap.

Bridging from protocol changes to real-world rollup adoption, let’s see how major Layer-2 teams are preparing.

4. Layer-2 Insights: How Rollups Plan to Leverage PeerDAS Major rollups are already updating infrastructure for PeerDAS: • Parithosh Jayanti (EF) anticipates a significant “blob limit bump,” cutting rollup costs and improving ZK-proof efficiency. • Arbitrum operators must upgrade beacon-chain RPC providers to support historical blob subscriptions for Nitro nodes ahead of Sepolia’s October 14 and mainnet’s December 3 forks. These preparations enable rollup teams to refine fee models, run gas-efficiency audits, and optimize batch sizes— positioning them to capitalize on expanded blobs and reduced sampling costs.

5. The MEV Factor: What 60 M Gas Blocks Mean for Extractable Value While larger blocks boost throughput, they reshape MEV dynamics. Flashbots research shows MEV bots consume over 50% of space on high-capacity rollups like Base, yet contribute under 10% of fees. Base’s November 2024–February 2025 11 M gas/s capacity increase filled almost entirely with low-value bot activity, limiting benefits for genuine users. Post-Fusaka, aggressive MEV strategies could again crowd out real transactions. Mitigation will rely on dynamic priority-fee markets, EIP-1559’s base-fee burn, and MEV-sharing protocols that channel value back to users. TokenVitals’ analytics will track effective gas throughput and MEV density, alerting investors when bot activity threatens net user capacity.

6. Developer Action Items: Preparing for Fusaka’s December 3 Fork To hit the ground running:

7. Upgrade client software (Geth, Besu, Erigon, Nethermind) to Fusaka-compatible versions

8. Test contracts and deployment scripts against the 16.78 M gas cap on Holesky, Sepolia, and Hoodi testnets

9. Conduct gas-efficiency audits to optimize batch sizes and leverage BPO parameters

10. Monitor validator signals via on-chain GasLimits data to ensure the 50% support threshold is met

Comparative Sidebar: Fusaka vs. Solana Firedancer vs. MegaETH’s 1 ms Blocks This snapshot benchmarks Fusaka’s parameters against two competing architectures: • Ethereum Fusaka: 60 M gas per 12 s block, PeerDAS sampling, single-tx cap & raised RLP limits, 30–50% L2 fee cuts • Solana Firedancer: Full-state replication, ~100–136 k TPS on testnet, multi-threaded C++ pipeline • MegaETH: Centralized sequencer, consensus-free parallel sync, 1 700 Mgas/s (~10 ms blocks)

Conclusion Fusaka marks a critical milestone in Ethereum’s scalability journey—boosting L1 capacity today while laying the technical groundwork for tomorrow’s parallel-execution and danksharding era. By raising gas limits, streamlining data availability with PeerDAS, and capping per-tx gas, Fusaka addresses immediate congestion pain points and primes the network for exponential growth. Developers should upgrade, test, and optimize now; investors can anticipate reduced fee volatility and clearer capacity signals. Together, these enhancements pave a smoother, more efficient road ahead for Ethereum’s vibrant ecosystem.