ASIC miner

ASIC stands for application-specific integrated circuit: a chip that does one job only. For mining, that job is computing a particular hash function as many times per second as possible. Because nothing is wasted on general-purpose features, an ASIC beats CPUs and graphics cards by orders of magnitude in hashes per unit of electricity.

Bitcoin mining moved from computers and GPUs to ASICs around 2013, and today the network's hashrate comes almost entirely from these machines, made by a handful of manufacturers such as Bitmain. Other coins, including Monero, have tuned their algorithms to resist ASICs so that ordinary hardware stays competitive.

ASICs are only useful for one algorithm, so their value collapses if the coin's price falls, its difficulty rises sharply or more efficient models arrive. Buyers should compare efficiency in joules per terahash against electricity costs, and account for noise, heat and the halving.