What is RISC-V, and why does Vitalik Buterin want it for Ethereum smart contracts?
* What is RISC-V? *
RISC-V, pronounced “risk five,” is a modern open-source instruction set architecture (ISA) based on reduced instruction set computer (RISC) principles. In simple terms, it’s 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 tailor its functionality and use cases, plus offers cost savings compared to proprietary ISAs like ARM or x86. This offers a wide range of uses, from supercomputers to smartphones and now blockchains like Ethereum.
On April 20, 2025, Ethereum co-founder Vitalik Buterin unveiled a “radical” new scaling proposal to replace the Ethereum Virtual Machine (EVM) with the RISC-V instruction set architecture, aiming to boost the speed and efficiency of the network’s execution layer. The idea is that RISC-V is the best way to solve the blockchain’s scalability constraints.
“It aims to greatly improve the efficiency of the Ethereum execution layer, resolving one of the primary scaling bottlenecks, and can also greatly improve the execution layer’s simplicity - in fact, it is perhaps the only way to do so.
The idea: replace the EVM with RISC-V as the virtual machine language that smart contracts are written in,” said Buterin.
Ethereum continues to face high transaction fees and reduced transaction volume as users shift to layer 2s for cheaper, faster transactions. This aligns with Ethereum’s scaling strategy post-Merge (2022). Buterin’s idea to reshape the chain is seen as a chance for it to modernize and retain its dominance as a top smart contracting platform.
*Did you know?* Ethereum’s execution layer has become its main scalability bottleneck. The inefficient processing of smart contracts and transactions due to single-threaded execution, wasteful computational design and complex state management is causing network congestion.
* How would RISC-V work on Ethereum? *
Adding RISC-V to Ethereum is still just a proposal being discussed by the community and network governance. Buterin outlines several approaches to implement the proposal, including running two virtual machines (VMs) or a complete switch to RISC-V.
The first idea to support VMs would enable contracts to be written and executed in either the existing EVM model or RISC-V. Both contract types would have access to functionality such as persistent storage, holding Ether (ETH) balances and making and receiving calls. Adding to this, the contract could integrate so they can call one another.
An alternative approach, described as “more radical,” would modify the protocol to convert existing EVM contracts. This would require rewriting current contracts to interact with an EVM interpreter, while new contracts would be written directly in RISC-V.
A major challenge for such a drastic change is to avoid breaking existing decentralized applications (DApps) and smart contracts. Ethereum can’t risk breaking existing contracts written in the current EVM code. A transitional solution could involve using an interpreter — essentially a translation layer between different computing languages. This would allow developers to begin building with RISC-V while ensuring legacy EVM contracts continue to function without disruption.
*Did you know? *In 2022, Ethereum made a leap forward in its energy efficiency and delivered more scalability, security and sustainability. In a process dubbed “The Merge,” the chain switched from a proof-of-work (PoW) consensus mechanism to proof-of-stake (PoS). This involved merging the Ethereum mainnet with a separate PoS blockchain called Beacon Chain.
* Key benefits of RISC-V vs. EVM *
If RISC-V causes a major shift in the Ethereum architecture, what will be the benefits of making this change? In the long run, RISC-V would enhance the Ethereum smart contracts’ performance and processing.
According to Buterin, the new architecture could theoretically deliver efficiency gains of 100x; in reality, this number will be hard to reach, but gains would still be significant. The efficiency gains are tied to RISC-V’s suitability for both zero-knowledge (ZK) proof systems and general smart contract execution, as it eliminates EVM overhead.
It’s less about replacing the EVM outright and more about using RISC-V as a backend for zkEVM or similar ZK rollups, where proving costs dominate. Scalability improvements would largely come from offloading execution to ZK rollups, with RISC-V optimizing the proving process.
RISC-V smart contracts could run faster and use fewer computational resources. This increased efficiency would likely translate to lower gas fees for the end users. In the process, it would also enable the network to handle more users and transactions without slowing down. That would be a direct improvement to the scalability of Ethereum, potentially solving one of the biggest criticized points of the blockchain industry.
Additionally, RISC-V’s simple, flexible instruction set is better suited for ZK-proof computations than the EVM, which incurs overhead from administrative tasks like gas accounting and state management.
Rather than rebuilding the EVM for ZK-proofs, RISC-V offers a streamlined alternative, simplifying the development of ZK-optimized execution layers. This could accelerate Ethereum’s roadmap for privacy and scalability via ZK rollups, making RISC-V a compelling complement to the EVM.
Below is a comparison table summarizing the key differences and benefits of RISC-V vs. the EVM.
*Did you know?* Ethereum has gone through several major development milestones over its first decade. Notably, in 2016, it conducted a hard fork to roll back the chain after The DAO hack. The result is still noticeable today with Ethereum and Ethereum Classic chains both in existence.
* Will RISC-V be implemented in the future? *
Buterin’s proposal has sparked a lively debate among Ethereum users and developers. It is an ambitious idea that could be a milestone in the development roadmap for the leading smart contract blockchain.
Programmer Ben Adams raised several concerns about the proposal: In short, the ZK-proof might become more efficient, but there could be a trade-off. Block building and execution, which run the smart contracts, could end up becoming significantly slower.
“The risk here is that ZK-proving may get better, but block building and execution will deteriorate significantly,” commented Ben Adams.
A sentiment that was echoed by another anonymous commenter, “I agree with Ben Adams here, The EVM as a whole is very much U256 based, so abstracting down to RISC-V would decrease overall execution performance.”
Others appeared to agree that RISC-V was a good idea to help reduce bottlenecks but questioned if it was a priority, given the potential technical difficulty and cost.
“Agree, it seems like a good idea for the L1 that solves points 2 and 3 of the L1 bottlenecks. But is this the set of priorities we want to solve for, especially given the scale of technical cost here?” added Adam Cochran.
It’s clear that the proposal still needs clarity and further discussions within the Ethereum community. While the promise is one of radical simplification that drives efficiency and speed, it also introduces a complex technical change. It would require potentially years of dedication to rethinking how the layer-1 blockchain works.
Of course, as with any decentralized project, the green light doesn’t just rely on technical planning; it needs the consent of the community. So, currently, Buterin’s proposal has opened a wide conversation about any impending development action.