Sui blockchain, launched just one year ago, is another blockchain that leverages parallel execution to ensure high transaction output. This article explains what Sui is and how it utilizes parallel execution.

Sui mainnet went live on May 3rd, 2023 after months of preparation. Mysten Labs developed the blockchain and it has its own virtual machine (Sui Virtual Machine). The Sui Virtual Machine processes smart contracts that are written in Move language.

Objects

Unlike blockchains that use accounts as the storage unit, Sui uses objects. Objects are created by developers through smart contracts. Developers define, create, and oversee these programmable entities that embody user-level assets. Each entity possesses unique attributes, such as ownership, which can be modified according to the operational rules defined within the smart contract responsible for its creation.

Deterministic Execution

Like Solana, Sui implements a deterministic mode of parallel execution that requires the states of all transactions (dependent or independent) to be ascertained first to identify dependencies before execution is carried out. This approach creates more overhead complexity for developers, however, it reduces the time spent re-executing transactions that are. In fact, found to be dependent.

How transactions work in Sui - Object Centric Model

In Sui's design, because each object maintains its own independent ledger, a significant number of concurrently submitted transactions do not require sequential ordering. Only transactions that interact with the attributes of the same object(s) need to be sequenced. When two or more transactions are received by a validator simultaneously and do not involve overlapping objects, they can be recorded in the ledger simultaneously.

On Sui, due to its object-centric model, assets owned by the same individual exist independently. Each asset, even if they are of the same token type, is treated as a different object. Many transactions involving tokens of the same type owned by the same individual do not require sequential ordering. For instance, if Alice possesses 2 USDC tokens, it means she owns two separate 1-USDC objects. If she decides to send 1 USDC to two different recipients, these transactions can occur simultaneously without needing to be sequenced. This is because Sui is object-centric. In contrast, in an address-centric model, these types of transactions would require sequencing to verify that Alice has adequate USDC balance for both transactions.

Consensus Mechanism - Delegated Proof of Stake

Sui uses the delegated Proof of Stake (dPoS) consensus mechanism where interested validators must have a certain amount of SUI tokens to help secure the network.

Narwhal and Tusk - Two Parts of the Consensus Engine

Complex transactions on Sui require sequencing and consensus for finalization. The consensus engine on Sui comprises two components: Narwhal and Tusk.

Narwhal serves as the mempool, the waiting room for unverified transactions. This ensures that transaction data is accessible for validator processing.

Tusk, on the other hand, orders all transactions involving shared objects.

You can learn more about Sui blockchain here.