What is RISC-V and why does Vitalik want to use it for smart contracts?

Author: Marcel Deer, CoinTelegraph; Compiler: Baishui, Golden Finance

1. What is RISC-V?

RISC-V, pronounced "risk five", is a modern open source instruction set architecture (ISA) based on the principles of reduced instruction set computers (RISC). Simply put, it is like a blueprint that defines a set of instructions that a processor can execute.

RISC-V is designed to be highly modular, efficient, and flexible. Originally developed by the University of California in 2010, the open source framework gives developers the flexibility to customize its features and use cases, and saves costs compared to proprietary ISAs such as ARM or x86. RISC-V has a wide range of uses, from supercomputers to smartphones, and now blockchains such as Ethereum.

On April 20, 2025, Ethereum co-founder Vitalik Buterin announced a "radical" new expansion plan to replace the Ethereum Virtual Machine (EVM) with the RISC-V instruction set architecture, aiming to improve the speed and efficiency of the network execution layer. The idea is that RISC-V is the best solution to the scalability limitations of blockchain.

“It aims to significantly improve the efficiency of Ethereum’s execution layer, solve one of the main expansion bottlenecks, and significantly improve the simplicity of the execution layer - in fact, this may be the only viable solution.”

The idea is: replace EVM with RISC-V as the virtual machine language for writing smart contracts,” Buterin said.

Ethereum continues to face high transaction fees and declining transaction volume as users turn to Layer 2 in pursuit of cheaper and faster transactions. This is consistent with Ethereum’s expansion strategy after the merger in 2022. Buterin’s idea of ​​​​reshaping Ethereum is seen as an opportunity for Ethereum to modernize and maintain its dominance as a top smart contract platform.

Second, how does RISC-V run on Ethereum?

Adding RISC-V to Ethereum is still just a proposal being discussed by the community and network governance. Buterin outlined several ways to implement the proposal, including running two virtual machines (VMs) or switching to RISC-V completely.

The first idea of ​​supporting virtual machines is to allow contracts to run on the existing EVM model or RISC-V

Another option, described as "more radical," is to modify the protocol to convert existing EVM contracts. This requires rewriting existing contracts to interact with the EVM interpreter, while new contracts are written directly in RISC-V.

A major challenge with such a major change is to avoid breaking existing decentralized applications (DApps) and smart contracts. Ethereum cannot risk breaking existing contracts written in current EVM code. A transitional solution could involve using an interpreter - essentially a translation layer between different computing languages. This would allow developers to start building with RISC-V while ensuring that traditional EVM contracts continue to run without interruption.

III. Main advantages of RISC-V over EVM

If RISC-V leads to a major shift in Ethereum architecture, what benefits would this shift bring? In the long run, RISC-V Will improve the performance and processing power of Ethereum smart contracts.

According to Buterin, the new architecture can theoretically achieve a 100-fold efficiency improvement; in practice, this number is difficult to achieve, but the improvement is still very significant. The efficiency improvement is closely related to RISC-V's suitability for zero-knowledge (ZK) proof systems and general smart contract execution, because it eliminates the overhead of the EVM.

RISC-V is not a complete replacement for the EVM, but RISC-V is used as the backend of zkEVM or similar ZK Rollup, because in these systems, the cost of proof dominates. The scalability improvement mainly comes from offloading execution tasks to ZK Rollup, while RISC-V optimizes the proof process.

RISC-V smart contracts can run faster and consume fewer computing resources. This efficiency improvement is likely to translate into lower gas fees for end users. In the process, it will also enable the network to handle more users and transactions without slowing down. This will directly improve Ethereum's scalability and has the potential to solve one of the blockchain industry's most criticized problems.

In addition, RISC-V's simple and flexible instruction set is more suitable for zero-knowledge proof computations than the EVM, which incurs overhead for administrative tasks such as gas accounting and state management.

Rather than rebuilding the EVM to support zero-knowledge proofs, RISC-V provides a streamlined alternative that simplifies the development of a zero-knowledge optimized execution layer. This can accelerate Ethereum's roadmap to achieve privacy and scalability through zero-knowledge rollups (ZK Rollups), making RISC-V a more popular choice for EVM.

The following table summarizes the main differences and advantages of RISC-V and EVM.

Fourth, will RISC-V be implemented in the future?

Buterin’s proposal has sparked heated debate among Ethereum users and developers. This is an ambitious idea that could become a milestone on the development roadmap of the leading smart contract blockchain.

Programmer Ben Adams Several concerns were raised about the proposal: In short, zero-knowledge proofs may become more efficient, but there may also be some drawbacks. Block construction and execution for running smart contracts may end up being significantly slower.

“The risk here is that zero-knowledge proofs may get better, but block construction and execution will get significantly worse,” commented Ben Adams.

Another anonymous commenter expressed the same sentiment: “I agree with Ben Adams that the EVM as a whole is based on the U256 architecture, so abstracting to RISC-V will reduce overall execution performance.”

Others seemed to agree that RISC-V is a good idea to help reduce bottlenecks, but questioned whether it should be prioritized given the potential technical difficulty and cost.

“Agreed, it seems like a good idea for Layer-1 to solve points 2 and 3 of the Layer-1 bottleneck. But is it something we want to prioritize, especially given the scale of the technical cost? ” Adam Cochran added.

Obviously, the proposal still needs further clarification and discussion in the Ethereum community. While the proposal promises to radically streamline the process to improve efficiency and speed, it also introduces a complex technical change. It may take years to rethink how Layer-1 blockchains work.

Of course, as with any decentralized project, approval of the review depends on more than just technical planning; it requires community buy-in. Therefore, for now, Buterin's proposal has already sparked widespread discussion about any upcoming development actions.