‣
- Blocks in a blockchain have certain storage capacities in terms of the amount of data a single block may store. As mentioned above, the data that is stored in blockchain blocks are often a list of transactions. When a block reaches its capacity, it is closed and linked to the previous block. All of the data that arrives after this block is added is compiled into a new block. This block will also be added and linked to the blockchain once it reaches its capacity.
- Block time refers to the time it takes for a blockchain to create a new block. It is the time interval between the creation of each new block in a blockchain. The block time of a blockchain is determined by a number of different factors.
- These factors for proof-of-work blockchains can include the likes of the complexity of the hash being solved and the available computing power or hash rate. The block time for Bitcoin is currently around 10 minutes, while the block time for Ethereum is currently 10 to 15 seconds. The protocols behind these blockchains will adjust the mining difficulty periodically to ensure that the average block time for the blockchain remains the same.
‣
- The block size is what determines the quantity of data that can be stored within each block. Therefore, if a blockchain were to increase its block size, the blockchain will be able to increase the number of transactions per second that it may process.
- However, many negatives accompany increasing the block size. Larger blocks will grow the blockchain faster and make full nodes more expensive to operate. Full nodes are nodes that store the entire blockchain data on a hard drive rather than a simplified shorter version. As the blockchain grows faster, an increase in the data that must be stored by full nodes goes along with it.
- This change will increase the data storage costs of full nodes. Rising costs may cause more centralization, as it could both dissuade users to operate full nodes or cause users who operate full nodes to stop doing so. Any decrease in the number of users operating full nodes leads to an increase in centralization for the network.
‣
- Several alternatives exist to increasing the block size when it comes to improving the scalability of a blockchain. One alternative is the use of Layer 2 solutions. Layer 2 is a term used to describe a secondary protocol that is built on top of an existing blockchain.
- On this second layer, blockchain transactions and processes can take place independently of the original blockchain and still benefit from the decentralization and security of the original blockchain.
- Examples of Layer 2 solutions include the Bitcoin Lightning Network and the Polygon Network. Another alternative for improving scalability is to decrease the block time. However, decreasing the block time brings many downsides, including limited ability to scale because of the relay time. Relay time is the time needed to broadcast a new block to every node on the blockchain. If the block time falls below the relay time, then a new block will be generated before the old block can be received by all the nodes in the network.
‣
‣
- A blockchain’s block time matters because it has an impact on the network’s throughput. However, smaller block times are not always better because of the relay time of the network.
- Furthermore, block times are limited in their ability to help scale blockchains, and alternative updates to other parts of the blockchain protocol such as its consensus mechanism will have a much bigger impact on a network’s scalability.
‣