RISC-V as an Alternative to EVM: The Performance Breakthrough Path of Ethereum

The co-founder of Ethereum recently proposed a long-term initiative to the community: to replace the current execution layer virtual machine (EVM) with an open-source RISC-V instruction set architecture. He believes this may be the only way to achieve breakthroughs in execution layer performance and simplify protocol logic, especially in terms of zero-knowledge proof (ZK Proof) efficiency, which is expected to achieve up to 100 times optimization improvement. This proposal aims to address the bottleneck issues of Ethereum in ZK proof efficiency, block construction complexity, and data availability.

Current Limitations of EVM and Advantages of RISC-V

The main issues facing the EVM include:

• The architecture is outdated and incompatible with modern CPUs, resulting in low execution efficiency of ZK-EVM.
• The efficiency of ZK proofs is limited, with about half of the resources used for executing the EVM itself.
• Poor maintainability, chaotic standards, and difficult to abolish complex functions
• Development is restricted, mainstream languages are difficult to efficiently compile into EVM bytecode.

In contrast, RISC-V has the following advantages:

• High performance, hardware friendly, can be used for JIT optimization and even hardware acceleration.
• ZK optimization, directly generating circuits for RISC-V instructions is simpler than proving EVM operations.
• Mature toolchain, supporting mainstream languages, lower development threshold, and broader ecosystem.
• There are successful cases, such as Nervos CKB and other blockchains adopted.

Replacement Path and Challenges

Three replacement options were proposed:

1. Dual VM coexistence: EVM and RISC-V run in parallel, new contracts can optionally use RISC-V
2. On-chain interpreter solution: All EVM contracts are interpreted and executed by on-chain RISC-V contracts.
3. Interpreter plugin mechanism: Treat the interpreter as a protocol element, allowing for the future insertion of other VMs.

The technical challenges faced in implementation include:

• Execution performance degradation risk
• Gas pricing needs to be restructured
• Secure Sandbox Design
• Development tool adaptation
• Migration compatibility issues

Tending to adopt Plan One as a transitional path, committing to ensure interoperability between the old and new contracts and a seamless upgrade for users.

Impact on Existing Scalability Roadmap

RISC-V is an infrastructure optimization and will not replace the existing scaling route:

• Layer 2: Rollup remains the main force, RISC-V improves L1 processing efficiency and ZK verification performance.
• Data Sharding and EIP-4844: Data availability bottlenecks still need to be addressed.
• FaaS, MEV: Independent of the virtual machine architecture, not affected.

Community Feedback and Related Attempts

There are differences in the community:

• Supporters believe this is a necessary upgrade to address performance challenges.
• Conservatives are concerned about the implementation difficulties and the costs of ecological updates.

Reference projects:

• Move VM (Aptos/Sui)
• FuelVM
• WASM (Stylus)
• Nervos CKB

Future Impact Outlook

If Ethereum switches to RISC-V, it may bring the following changes:

• Developer Experience: Retain existing languages, may add support for new languages
• Operating costs and performance: Improved execution efficiency, optimized Gas model
• Ecological compatibility and development: coexistence of dual VMs transition, infrastructure needs to be adapted
• Security and Stability: Extensive testing and verification are required, with the hope of enhancing the reliability of the protocol.

This proposal represents Ethereum's deep consideration of the future limits of performance and protocol simplicity. Implementation will be a long-term process that must overcome multiple challenges. It does not overturn the existing roadmap, but prepares for the future; it is an exploration of whether the "underlying is worth reshaping."