Ethereum’s faster proofs face Vitalik’s next test: a hard cost limit

In an October 15 post, Buterin congratulated ZKsync's Airbender team and outlined three formal-verification priorities: matching execution to Ethereum's specification, bounding prover cost relative to block gas, and securing the proof system itself. The cost requirement extends beyond speed benchmarks to ensure resource accounting can keep up with faster proof generation.

Current analysis and performance

The current EIP-7904 analysis, which targets 100 million gas per second on optimized native execution clients, recommends no compute gas-cost changes. As of October 18, it's an Informational EIP in Last Call with a November 1 deadline. The analysis specifically addresses CPU execution but not ZK-SNARK proof generation, which imposes different workloads.

ZKsync demonstrated progress with its single-GPU evaluation, reporting that one NVIDIA RTX PRO 6000 Blackwell proved 99% of 7,200 consecutive Ethereum mainnet blocks in under 10 seconds each. The company also described separate live ETHproofs configurations using two and four GPUs.

Workload challenges

A maximum-cost guarantee must cover every permitted workload, including blocks deliberately assembled to be expensive to prove. This distinction matters for operators budgeting hardware, as typical blocks may fit small setups while difficult legal workloads determine reserve capacity.

In January measurements, Nethermind Research's Lin Oshitani found that cryptographic precompiles and several modular arithmetic operations were relatively expensive to prove per gas. Costs varied by prover, and ZK-cycle counts didn't translate into uniform proving time across operations.

Engineering responses

Engineering responses could include improving expensive circuits or execution paths to reduce proving work while leaving transaction execution gas unchanged. Nethermind's study also outlined weighted ZK-gas metering with a per-block ceiling that would count proof-heavy operations against a separate allowance.

Economically, a resource cap and payment rule answer separate questions. EIP-7999's multidimensional fee-market proposal remains Draft and separates calldata into its own resource, while opcode repricing would operate through the existing gas allowance.

Next steps

For independent provers, the consequential next step is establishing a bound tied to explicit workloads, implementations, security settings and hardware assumptions. This would turn a gas allowance into a dependable limit on proving resources operators must be ready to supply.

The Ethereum Foundation's January worst-case benchmarking framework relates required proving throughput to chosen block gas limits and proving deadlines. Under that approach, difficult blocks must still fit intended hardware and time budgets, considering proof generation's fixed overhead and nonlinear aggregation.