ViaBTC Introduction｜Things You Must Know about Mining: What Exactly are Empty Block, Orphan Block, and Uncle Block?
In crypto mining, Orphan Rate often pops up in mining pool statistics. For beginners, the term may look somewhat strange. During mining, other than regular blocks, there are also empty blocks, orphan blocks, and uncle blocks. Moreover, to a certain extent, the generation of these special blocks will also affect the income of miners.
Empty Block
In crypto mining, essentially a process of computation and packaging, miners first engage in a race of hashrates. Whoever solves the block first is allowed to update the block. These miners then need to package the trade information broadcast by users into the block and put it on the blockchain to be passed along.
If the winning miners did not package the trade information into the block, the block becomes an empty one. Containing zero trade information, empty blocks are only used for block rewards. As no trade is contained in an empty block, miners can only receive the most basic block reward, and the corresponding miner fee/gas fee will not be available.
Orphan Block
In a blockchain network, it takes time for blocks to get transmitted and broadcast. Therefore, two miners will have to compete if they have found blocks at the same height almost simultaneously. Though the second block is also generated during normal computation, due to “the longest chain” principle, this block created slightly later than the first will not be included in the main chain. In the Bitcoin network, such blocks, referred to as “orphan blocks”, should be discarded completely, and miners who generated an orphan block will not receive the relevant block reward.
The higher the orphan rate, the lower the mining income, and the more invalid blocks there will be. That is why mining pools and miners are exploring ways to lower the orphan rate. For instance, by referring to the broadcasting and transmission of the Bitcoin network, ViaBTC has technically optimized the broadcasting and transmission of the Bitcoin network through its self-developed Bitcoin client. The optimization allowed miners to spot and broadcast new Bitcoin blocks within shorter periods, thereby reducing the orphan rate and protecting miners’ returns.
Uncle Block
Orphan blocks also exist in Ethereum. However, due to Ethereum’s shorter block time, to prevent the mining pool from controlling the mining process as a result of excessive hashrates, and to avoid hashrate wastes, if a block in the main chain is willing to accept orphan blocks, then they become uncle blocks and are included in the main chain. Moreover, rewards will be offered to miners producing uncle blocks.
The uncle block mechanism aims to make the Ethereum network more secure. Due to Ethereum’s much shorter block time as compared with Bitcoin, temporary forks are more likely to occur. As a result, the main chain of Ethereum may not be the “heaviest” because of the high orphan rate, thus influencing the security of the main chain. Therefore, the introduction of a mechanism that turns orphan blocks into uncle blocks makes the network safer.
Miners of the referencing block get an inclusion reward of approximately 1/32 of the basic block reward. Of course, there are also some limits for the generation of uncle blocks. The uncle block must be a direct sub-block of blocks of the first two layers to the first seven layers of the block. Moreover, the uncle rewards diminish as the interval increases. For example, miners receive 7/8 of the basic block reward for a sub-block of blocks from the first two layers (one-layer interval), 6/8 for two-layer intervals, and so forth.
Overall, the miner fee/gas fee drops due to empty blocks. Furthermore, miners suffer a direct loss of income arising from excessive orphan rates (too much invalid computation) and receive certain rewards for including uncle blocks. As such, when investing hashrates, miners should consider pools with lower orphan rates for better income protection.
