VM Matters: A Comparison of WASM VMs and EVMs in the Performance of Blockchain Smart Contracts
This study addresses the unknown performance of eWASM versus EVM for blockchain developers and researchers considering the adoption of WASM as a next-generation blockchain environment.
This paper compares the performance of WebAssembly (WASM) VMs and Ethereum Virtual Machines (EVMs) for executing blockchain smart contracts. Surprisingly, the current WASM VM does not achieve expected performance, introducing non-trivial overhead compared to EVM.
WebAssemly is an emerging runtime for Web applications and has been supported in almost all browsers. Recently, WebAssembly is further regarded to be a the next-generation environment for blockchain applications, and has been adopted by Ethereum, namely eWASM, to replace the state-of-the-art EVM. However, whether and how well current eWASM outperforms EVM on blockchain clients is still unknown. This paper conducts the first measurement study, to measure the performance on WASM VM and EVM for executing smart contracts on blockchain. To our surprise, the current WASM VM does not perform in expected performance. The overhead introduced by WASM is really non-trivial. Our results highlight the challenges when deploying WASM in practice, and provide insightful implications for improvement space.