Ethereum’s scaling problem is not a new topic of discussion in the crypto world; This groundbreaking smart contract blockchain is notorious for high gas costs due to limited throughput during periods of high activity.
One of the main reasons behind the limited scalability is the sequential nature of Ethereum’s runtime environment, the Ethereum Virtual Machine (EVM). To provide a bit more context, the EVM is designed to function as a Turing-complete virtual machine, enabling the secure execution of smart contracts on the Ethereum blockchain.
Although this runtime environment is efficient and reliable, transactions are processed sequentially. This means that smart contract executions on the Ethereum blockchain are processed one after another, taking longer, especially during high-volume activities.
In the long term, Ethereum users face longer wait times and higher gas fees, as was the case when CryptoKitties first clogged the Ethereum network in 2017, and more recently during the DeFi and NFT market craze of 2021.
Parallel EVM: A New Dawn for the DApp Ecosystem
In recent years, several initiatives have been launched to solve Ethereum’s scalability challenge, including alternative Layer 1 chains such as Solana and Layer rollups such as Arbitrum and Optimism.
While these scalability solutions have played a notable role in improving transaction throughput, a newer scaling solution is currently emerging in the DeFi community; parallel EVM chains such as Sui, Meter and Nomad are changing the game by introducing DApp building ecosystems that can process multiple smart contract transactions simultaneously.
Let’s put it into perspective; In the standard EVM model, if Alice and Bob submit transactions to send X amount of an Ethereum native token to different addresses, the EVM will process the transactions in a sequential order depending on which transaction was initiated first initiated. This means that one of them would have to wait longer for its smart contract order to be executed, despite the transactions being independent of each other.
However, in a parallel EVM model, the two transactions would be submitted at the same time, reducing latency and gas costs. The analogy is similar to that of a multi-core CPU where each core can simultaneously process or execute independent instructions, which has significantly increased the processing power of modern computers.
There are two main approaches to EVM parallelization: optimistic parallelism and the state access method.
Optimistic parallelism: As the name suggests, an optimistic parallel EVM model initially assumes that all transactions are inherently independent. Once the transaction is executed, the model then verifies the assumption and corrects any dependent transactions that could have been executed independently. The caveat to this model is that it can lead to many conflicts after a transaction is executed, especially when processing dependent transactions.
State Access Method: Unlike the first, this approach proactively sorts dependent and independent transactions. This allows smart contracts to execute dependent transactions in a sequential format, while processing independent transactions one after the other. On the plus side, there are no retroactive changes, but on the other hand, it costs developers more resources and time to proactively execute the transactions.
Parallel EVM Smart Contract Blockchains
While a novel solution to Ethereum’s scaling bottlenecks, some DApp-compatible blockchains are already leading the way. This section briefly highlights three major parallel EVM chains that use this approach to solve Ethereum’s scalability limitations.
Sui
With a total value locked (TVL) of $751 million, the Sui blockchain ecosystem is designed as a parallel EVM chain, using the state access method. Notably, this smart contract network also features an object-centric data model to increase clarity when proactively ordering independent and dependent transactions. At the time of writing, there are more than 25 DApps building on the Sui blockchain ecosystem, most of which are Dexes and yield platforms.
Meter
This is another EVM-compatible chain that has already integrated parallel transaction submission on its mainnet. What’s further notable about Meter’s approach to Ethereum scalability is the project’s upcoming crypto-optimized database that will improve I/O performance by 3x and reduce the disk footprint to ⅓ of the PebbleDB used by Ethereum today. Other differentiators include Front Running/MEV Resistance, multi-asset validation, and higher security and liveliness, thanks to a combination of PoW and PoS consensus.
Monad
Unlike the Sui blockchain network, Monad uses the optimistic parallelism method and claims to support more than 10,000 transactions per second. The project’s co-founder and CEO, Keone Hon, spoke to Blockworks earlier this year and emphasized the importance of using separate threads to enable concurrent transactions by virtual machines like the EVM, all while maintaining a simple UI/ UX for DeFi natives.
“Monad can, in principle, use transaction formats exactly the same as Ethereum and then, under the hood, implement parallelism without any change from the user perspective.” said Hon.
Conclusion
The DApp ecosystem has grown significantly over the past four years and it is clear that mass adoption cannot happen until the scalability issues are solved. While some DeFi enthusiasts might argue for migration to cheaper DApp ecosystems, the reality is that Ethereum is still the most prominent smart contract blockchain, accounting for more than 50% of the total value (TVL) according to DeFi Llama.
Therefore, it makes more sense to develop scaling solutions that enhance Ethereum’s core functionalities or address multiple challenges simultaneously, such as EVM compatibility and parallel transaction processing.