Why do we need ASIC miners to mine Bitcoin?

The acronym ASIC stands for ‘application-specific integrated circuit’, which is a microchip designed for a particular purpose or task.   

An ASIC miner is a computer which is designed for the sole purpose of cryptocurrency mining.

Bitcoin uses Proof-of-Work (PoW) as its consensus mechanism, and new Bitcoin are generated through a computing process called ‘mining’.  

In January 2009, when Bitcoin’s creator, Satoshi Nakamoto, mined the first block, the CPU (central processing unit) of an average personal computer was sufficiently powerful to accomplish this task, so the first Bitcoin miners did not require any specialised equipment for the task.  

For the first year of Bitcoin’s existence, with the price at or around $0, it continued to be possible to mine Bitcoin on a personal computer. 

As awareness for Bitcoin grew, more people started to mine the new digital currency, causing the difficulty rate to increase, which increased the amount of computing power needed to mine Bitcoin successfully.    You can learn more about the difficulty rate here.

By 2010, CPUs no longer had sufficient computing power for this task, and GPUs (graphics processing units) were increasingly used because of their enhanced mathematical computation capability.  GPUs were much faster and more cost efficient at mining Bitcoin than CPUs.

With the hype around Bitcoin ever-growing, and the difficulty rate on a never-ending upwards trajectory, GPUs soon also became insufficiently powerful to solve the mathematic puzzle in time.

For a brief period, FPGAs (field programmable gate arrays) were put to the task, but these proved to be too labour-intensive to build and too expensive to run, so their application for Bitcoin mining was short-lived.

It was now time to bring in the big guns.   In 2013, the first Avalon ASIC miner, designed specifically for Bitcoin mining, was released in by Canaan Creative, a Chinese computer manufacturer.  Shortly afterwards, other competing brands came flooding on to the market, starting with the Antminer S1 by Bitmain launched in November 2013.  

Competition in the ASIC miner market remains fierce, with manufacturers constantly developing ever more powerful and efficient models.  Bitmain’s Antminer S19 PRO is widely considered to be the current market leader in performance and efficiency.