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

Written by: Marcel Deer, CoinTelegraph

Compiled by: Baishui, Golden Finance

1. What is RISC-V?

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

The design goal of RISC-V is to be highly modular, efficient, and flexible. This open-source framework was initially developed by the University of California in 2010, allowing developers to customize its features and use cases flexibly, while also saving costs compared to proprietary ISAs like ARM or x86. RISC-V has a wide range of applications, from supercomputers to smartphones, as well as blockchains like Ethereum today.

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

"It aims to significantly improve the efficiency of the Ethereum execution layer, address one of the major scalability bottlenecks, and greatly enhance the simplicity of the execution layer—in fact, this may be the only viable solution."

Its philosophy is to replace EVM with RISC-V as the virtual machine language for writing smart contracts, "Buterin said.

As users shift to Layer 2 in pursuit of cheaper and faster transactions, Ethereum continues to face the issue of high transaction fees and declining transaction volumes. This aligns with Ethereum's scaling strategy following the merger in 2022. Buterin's vision for reshaping Ethereum is seen as an opportunity for Ethereum to modernize and maintain its dominance as a leading smart contract platform.

2. How does RISC-V run on Ethereum?

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

The primary idea of supporting virtual machines is to allow contracts to be written and executed within the existing EVM model or RISC-V. Both types of contracts can access persistent storage, hold Ether balances, and initiate and receive calls, among other functionalities. Furthermore, contracts can also be integrated to call each other.

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

One of the main challenges facing such a significant change is to avoid disrupting existing decentralized applications (DApp) and smart contracts. Ethereum cannot risk breaking existing contracts written in the current EVM code. A transitional solution may involve the use of an interpreter - essentially a conversion 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.

3. The Main Advantages of RISC-V and EVM

If RISC-V leads to a significant transformation in the Ethereum architecture, what benefits would this transformation bring? In the long run, RISC-V will enhance the performance and processing capabilities of Ethereum smart contracts.

According to Buterin, the new architecture could theoretically achieve a 100-fold increase in efficiency; in reality, this figure is difficult to reach, but the improvement is still very significant. The increase in efficiency is closely related to the applicability of RISC-V to zero-knowledge (ZK) proof systems and general-purpose smart contract execution, as it eliminates the overhead of the EVM.

RISC-V does not completely replace EVM, but rather uses RISC-V as the backend for zkEVM or similar ZK Rollups, as the cost of proof dominates in these systems. The improvement in scalability mainly comes from shifting execution tasks to ZK Rollups, while RISC-V optimizes the proof process.

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

In addition, the simple and flexible instruction set of RISC-V is more suitable for zero-knowledge proof computation than EVM, as EVM incurs overhead from management tasks such as gas accounting and state management.

RISC-V is not a reworked EVM to support zero-knowledge proofs, but rather provides a streamlined alternative that simplifies the development of zero-knowledge optimized execution layers. This can accelerate Ethereum's roadmap for achieving privacy and scalability through zero-knowledge rollups (ZK Rollup), making RISC-V a powerful complement to the EVM.

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

Fourth, will RISC-V land in the future?

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

Programmer Ben Adams raised a few concerns about the proposal: in short, zero-knowledge proofs may become more efficient, but there may also be some drawbacks. The block construction and execution of running smart contracts may ultimately slow down significantly.

The risk here is that while zero-knowledge proofs may improve, the construction and execution of the blockchain could significantly deteriorate, commented Ben Adams.

Another anonymous commenter expressed the same view: I agree with Ben Adams that the EVM is overall based on the U256 architecture, and thus abstracting to RISC-V would reduce overall execution performance.

Others seem to agree that RISC-V is a good idea to help reduce bottlenecks, but considering the potential technical difficulties and costs, they question whether it should be prioritized.

I agree, addressing the second and third points of the Layer-1 bottleneck seems like a good idea for Layer-1. But is this the issue we want to prioritize? Especially considering the scale of technical costs? Adam Cochran added.

Clearly, the proposal still needs to be further clarified and requires further discussion within the Ethereum community. While the proposal promises to thoroughly simplify processes to improve efficiency and speed, it also introduces a complex technological shift. This may take years to rethink the way Layer-1 blockchains operate.

Of course, as with any decentralized project, the approval of the approval does not solely rely on technical planning; it requires community recognition. Therefore, at present, Buterin's proposal has sparked extensive discussions about any upcoming development actions.