Ever since the creation of Bitcoin, Bitcoin mining has gone through four stages of change: CPU mining, GPU mining, Specialized Mining Chips (ASIC), Mining pools.
January 3rd 2009, Bitcoin’s creator Satoshi Nakamoto mined the first batch of Bitcoins using PC CPU. As more people accept Bitcoins, more miners started to appear, increasing the network’s computing power, therefore, increasing the mining difficulty.
September 18th 2010, the first GPU mining software was released. One GPU’s power rivals dozens of CPUs, significantly increasing mining capabilities.
Later, people start equipping their mining rigs with powerful ASIC chips. Currently, the industry-leading AntMiner rig contains 200 BM1387 chips, equivalent to around 30,000 GPUs’ computing power.
As more mining rigs join the fray, it becomes more difficult to solo mine Bitcoins. Therefore, miners come together with their rigs to form a mining farm or mining pool.