Solana is a high performance modern blockchain with impressive throughput capabilities. It can handle 50,000 transactions per second which makes it scalable and fast enough to enable a new era of decentralised applications (dApps).
Termed by Vitalik Buterin, the blockchain trilemma addresses the challenges developers face in creating a blockchain that is scalable, decentralized and secure — without compromising on any aspect.
The scalability problem has plagued many blockchains (e.g. Bitcoin, Ethereum) since almost day one. Blockchain ledgers and decentralized payment networks provide decentralized security to users — but usually, the more decentralized security they provide, the longer it can take for new transactions to be verified and added to the blockchain. These networks are faced with the challenge of providing ample transaction speed as their user count and transaction volume continues to increase, while still preserving the security and decentralization of the network.
Solana's value proposition against other layer 1 blockchains is simple: to be the fastest and cheapest blockchain that supports smart contract capabilities, while not compromising on its security and decentralization. Unlike its L1 competitors (ETH 2.0/BSC/DOT/ATOM), it achieves scalability without sharding. Solana maintains a single shared state and synchronous composability for every application on Solana.
📜 Source: What is Solana? A Scalable, Decentralized Network for Dapps by Decrypt
One of Solana’s key distinguishing features is its Proof of Stake (PoS) consensus system, which is reinforced by something known as Tower Consensus. This is a variant of a system that enables distributed networks to reach consensus despite attacks from malicious nodes, known as Practical Byzantine Fault Tolerance (PBFT).
Solana's implementation of PBFT enforces a global source of time across the blockchain through a second novel protocol known as Proof of History (PoH). This essentially provides a chronicle of previous events on the blockchain, ensuring that there's a common record of what happened and when for permanent reference.
Tower Consensus leverages this synchronized clock to reduce the processing power needed to verify transactions, since the timestamps of previous transactions no longer need to be computed. This helps Solana achieve a throughput that dwarfs most competitors.
Solana's transaction parallelization technology, known as Sealevel, allows for a parallel smart contracts runtime that optimizes resources and ensures that Solana can scale horizontally across GPUs and SSDs, which should help the platform scale to meet demands.
Solana also completely nixes the mempool system used by other platforms, and instead forwards transactions to validators even before the previous batch of transactions is finalized. This helps to maximize confirmation speed and boost the number of transactions that can be handled both concurrently and in parallel. This technology is known as 'Gulf Stream'.