Vitalik Buterin Proposes Replacing EVM Bytecode with RISC-V Architecture

Background and rationale for the proposal

Ethereum, the leading blockchain platform for smart contracts, has faced a number of scalability challenges in recent years. While layer-2 (L2) solutions have helped reduce the load on layer-1 (L1) and lower transaction fees, Buterin believes that the EVM — the core of Ethereum’s smart contract execution — is becoming a long-term bottleneck. According to Buterin, the current EVM bytecode is inefficient in supporting techniques such as zero-knowledge proofs (ZK-proofs), which are key to speeding up transactions, reducing costs, and improving privacy.

RISC-V, an open-source instruction set architecture, was proposed by Buterin as an alternative. Unlike EVM bytecode, which was designed specifically for Ethereum, RISC-V is a common hardware standard, already used in a wide range of applications from embedded devices to servers. RISC-V's strengths lie in its flexibility, efficiency, and compatibility with modern zero-knowledge tools. Buterin argues that switching to RISC-V could improve the performance of the execution layer by up to 100x, especially in generating ZK proofs, while simplifying Ethereum's overall architecture.

The proposal comes as Ethereum transaction fees have fallen to their lowest level since 2020 ($0.16 in April 2025), as most activity has shifted to L2 solutions. However, this has also reduced layer-1 revenue, raising concerns about the long-term value of Ether (ETH). Buterin believes that reforming the execution layer is necessary for Ethereum to remain competitive against high-performance blockchains such as Solana or Sui.

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Buterin’s proposal doesn’t aim to overhaul the entire Ethereum ecosystem, but focuses on improving the execution layer. Core elements like accounts, smart contract storage, ETH balances, and calls between contracts will remain the same. The main difference lies in how contract code is compiled and executed:

• Compiling code: Instead of compiling languages ​​like Solidity or Vyper to EVM bytecode, developers compile directly to RISC-V. This removes an intermediate layer, reducing computational costs.

• Opcode changes: Current opcodes like SLOAD or CALL will be replaced with syscalls in the RISC-V system, simplifying the execution process.

• Backward compatibility: Buterin proposed several options to ensure existing EVM contracts still work, including running both EVM and RISC-V contracts in parallel, using a RISC-V interpreter to execute legacy EVM bytecode, or integrating interpreters into the Ethereum protocol to support more virtual machines like Move in the future.

Buterin emphasized that developer tools and workflows will be minimally impacted. Solidity and Vyper will remain the primary languages, and new RISC-V contracts will be compatible with legacy EVM contracts, ensuring the ecosystem remains intact.

Potential benefits

• Increased performance and scalability: Moving to RISC-V can reduce on-chain execution costs by up to 100x in some cases, especially when combined with ZK-proofs. This makes Ethereum more competitive with high-performance blockchains.

• Simplifying the architecture: RISC-V, being open source and standardized, could reduce the complexity of the execution layer, allowing for future improvements. Buterin compares this proposal to the “beam chain” effort in the consensus layer, which has significantly simplified Ethereum’s processes.

• Increased Competition: By improving the efficiency of ZK functions and maintaining competition in the block production market, Ethereum can attract more developers and users.

• Expanding Compatibility: Integrating an interpreter into the protocol could allow Ethereum to support other virtual machines, creating a more flexible ecosystem.