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ZKsync Airbender zkVM

· 9 min read
Dora Noda
Dora Noda
Software Engineer

What if proving an Ethereum block took 35 seconds instead of requiring a warehouse of GPUs? That's not a hypothetical—it's what ZKsync's Airbender is delivering today.

In the race to make zero-knowledge proofs practical for mainstream blockchain infrastructure, a new benchmark has emerged. Airbender, ZKsync's open-source RISC-V zkVM, achieves 21.8 million cycles per second on a single H100 GPU—more than 6x faster than competing systems. It can prove Ethereum blocks in under 35 seconds using hardware that costs a fraction of what competitors require.

The Proving Problem​

Zero-knowledge proofs have long promised a cryptographic revolution: the ability to verify computations without revealing underlying data. For blockchains, this means compressing thousands of transactions into a single proof that any node can verify cheaply. The technology enables scaling without sacrificing security.

The catch has always been computational overhead. Generating ZK proofs is expensive—both in time and hardware. Until recently, proving a single Ethereum block required anywhere from 50 to 160 GPUs working in parallel, with proof generation times measured in minutes rather than seconds. At these costs, ZK technology remained limited to specialized Layer 2 rollups rather than becoming ubiquitous infrastructure.

The zkVM competitive landscape has intensified rapidly. Succinct's SP1, RISC Zero, a16z's Jolt, and now Airbender are racing to achieve what the Ethereum Foundation calls "real-time proving"—generating proofs fast enough to keep pace with block production itself. According to Ethereum Foundation researcher Justin Drake, "Real-time proving is a massive unlock for Ethereum" because it "enables us to scale the Layer 1 using ZK validators and ZK execution clients."

Airbender's Technical Architecture​

Airbender implements the RISC-V 32I+M instruction set—the same open standard that's becoming dominant in zkVM design. The architecture operates in a standard fetch-decode-execute loop, processing bytecode loaded via ROM in chunks of approximately 4 million cycles. Prover performance scales horizontally by "stitching" these chunks together via memory arguments.

The system supports three proving configurations:

  • CPU-only: Sufficient for development and testing
  • Single GPU: Production-ready for most use cases
  • Multi-GPU: Maximum throughput for high-volume applications

For GPU configurations, the CPU handles RISC-V simulation and tracing while the GPU computes witness generation and subsequent proving steps. This division of labor optimizes for the computational characteristics of each processor type.

Key technical differentiators include:

Mersenne31 Field Arithmetic: Airbender uses fast arithmetic operations specifically optimized for STARK performance, contributing to its speed advantage.

STARK-Based Proofs: Unlike SNARK-based systems, Airbender's STARK foundation provides quantum resistance without additional cryptographic overhead. The modular design allows upgrades as new cryptographic standards emerge.

Linear GPU Scaling: On a single RTX 4090, Airbender proves 9.7 million cycles per second. Performance scales linearly across multiple GPUs, enabling operators to trade hardware for speed as needed.

Benchmark Showdown: Airbender vs. the Competition​

The zkVM landscape has three primary competitors: Succinct's SP1, RISC Zero, and a16z's Jolt. Each represents a different approach to the proving problem, and real-world benchmarks reveal stark differences.

Single-GPU Performance (H100)​

SystemCycles/SecondRelative Speed
Airbender21.8 MHz1x (baseline)
SP1 Turbo3.45 MHz6.3x slower
RISC Zero1.1 MHz19.8x slower

Ethereum Block Proving​

For the critical use case of Ethereum block verification:

  • Airbender: ~35 seconds on a single H100 GPU; 17 seconds without recursion
  • SP1 Hypercube: ~12 seconds, but requires 50-160 GPUs (roughly equivalent to H100s)
  • Brevis Pico: 6.9 seconds average using 64 RTX 5090 GPUs

The hardware requirements tell the real story. Airbender achieves comparable performance to multi-GPU setups using a single commodity GPU. At current cloud pricing, this translates to proving costs of approximately $0.0001 per transfer—more than 10x cheaper than ZKsync's previous Boojum prover.

End-to-End Performance​

When measuring complete proof generation including recursion:

  • Airbender is 2.5-4x faster than SP1 Turbo
  • Airbender is 8.5-11x faster than RISC Zero

According to Ethproofs data, using a single RTX 4090, Airbender achieves an average verification time of 51 seconds at a cost of less than one cent—both metrics represent the best results among zkVMs.

The zkVM Competitive Landscape​

The race to build the fastest zkVM isn't purely academic. These systems underpin the next generation of blockchain infrastructure: cross-chain bridges, rollups, and eventually the Ethereum base layer itself.

SP1 (Succinct)​

SP1's strength lies in GPU acceleration and cryptographic precompiles optimized for blockchain workloads. The SP1 Hypercube, announced in late 2025, demonstrated real-time Ethereum proving in under 12 seconds—but required massive parallelization. SP1 excels in specific cryptographic operations and has strong developer tooling, but requires GPUs with more than 24GB VRAM for production workloads.

RISC Zero​

RISC Zero pioneered the production-ready zkVM category and remains highly competitive. The system claims to be at least 7x less expensive than SP1 in cloud deployments and up to 60x cheaper for small workloads. RISC Zero's zkVM 1.0 supports dApp interoperability across Ethereum, Base, Optimism, Arbitrum, World Chain, and Starknet.

Jolt (a16z)​

Jolt represents a novel approach to zkVM design, with early benchmarks showing 6x improvements over RISC Zero and 2x over SP1. However, Jolt remains in beta (v0.1) and faces production deployment challenges.

Where Airbender Fits​

Airbender's open-source, MIT-licensed approach differentiates it from competitors. Enterprises can run the prover themselves or with any hosting provider—no vendor lock-in. The STARK-based architecture provides quantum resistance without the trusted setup requirements of SNARK systems.

Independent analysis from Fenbushi Capital characterized the zkVM market in terms of three strategic orientations:

  • Performance-oriented: Brevis Pico, SP1, Jolt, and Zisk focus on low latency and real-time proofs
  • Modularity and scalability: OpenVM, Pico, and SP1 emphasize pluggability
  • Ecosystem and general development: RISC Zero, SP1, and ZiSK focus on SDK and language compatibility

Airbender competes primarily on raw performance while maintaining open-source accessibility.

Production Deployment: Already Live​

Unlike many zkVM announcements, Airbender isn't vaporware. The system is live on mainnet, powering chains that leverage the ZKsync Atlas Upgrade. All new ZKsync Chains will use Airbender as their proof system, replacing the Boojum prover.

Current and upcoming deployments include:

  • Abstract: Consumer-focused chain built on ZK Stack
  • Sophon: Gaming and entertainment chain
  • GRVT: Hybrid derivatives exchange
  • Lens: Decentralized social protocol
  • Memento: NFT and media chain

For developers, hardware requirements are accessible:

  • Development: Laptop CPU sufficient
  • Production: Any GPU with 22GB RAM (RTX 4090, RTX 5090, L4, or H100)

The code is available on GitHub at matter-labs/zksync-airbender, containing RISC-V circuits, a simulator, and utilities for witness generation, proof creation, and verification.

2026 Roadmap: From Fastest to Universal​

ZKsync's 2026 roadmap positions Airbender as more than a performance leader—it's intended to become a "universal standard" for zero-knowledge proving. Key initiatives include:

Deeper Auditing and Formal Verification: Production-grade security for institutional deployments requires rigorous verification beyond performance benchmarks.

Developer Experience Improvements: Making Airbender accessible to developers who aren't cryptography experts expands the potential user base significantly.

Cross-Ecosystem Expansion: Airbender's ambitions extend beyond ZKsync and Ethereum to become infrastructure for any blockchain requiring ZK verification.

The broader market context supports this ambition. The global zero-knowledge proof market is projected to reach $7.59 billion by 2033, growing at 22.1% CAGR. Over $28 billion in Total Value Locked sits across ZK-based rollups today.

Why This Matters Beyond Benchmarks​

The real significance of Airbender lies in what fast, cheap proving enables:

Native Rollups: Rather than relying on multisigs or governance for security, ZK rollups can achieve "native" security through cryptographic verification. This eliminates trust assumptions that currently make many rollups effectively centralized.

ZK Validators and Execution Clients: Real-time proving enables the Ethereum base layer itself to leverage ZK verification, potentially increasing throughput without compromising decentralization.

Cross-Chain Security: zkVMs enable verifiable computation across chains. A proof generated on one network can be verified on another, creating the foundation for trustless bridging without the oracle vulnerabilities that have plagued cross-chain protocols.

AI Verification: As AI systems increasingly make consequential decisions, ZK proofs can verify AI computations without revealing proprietary model weights. Airbender's performance makes such verification practical for real-world applications.

The transition from "ZK as a research curiosity" to "ZK as production infrastructure" is happening now. Brevis recently announced its Pico zkVM met the Ethereum Foundation's Real-Time Proving indicators (>96% sub-10s proofs, <$100K cost). Succinct's SP1 Hypercube demonstrated similar capabilities. Airbender joins this vanguard with a focus on hardware efficiency and open-source accessibility.

The Bottom Line​

Airbender's 6x speed advantage and 10x cost reduction over previous systems aren't incremental improvements—they represent a step change in what's economically viable. When proving costs drop below $0.0001 per transfer, ZK verification becomes practical for use cases previously dismissed as too expensive.

ZKsync has been working at the bleeding edge of ZK technology since 2018. With Airbender, the team has delivered infrastructure that makes zero-knowledge proofs practical for mainstream deployment. Whether it maintains its performance lead against rapidly iterating competitors remains to be seen, but the benchmark has been set.

The age of practical, cheap, fast ZK proving has arrived.

BlockEden.xyz provides enterprise-grade blockchain infrastructure supporting ZK-enabled networks and Layer 2 solutions. As zero-knowledge technology moves into production, our RPC endpoints and indexed data services help developers build on the cutting edge. Explore our API marketplace to access the infrastructure powering next-generation blockchain applications.

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