What is Inside an ASIC Bitcoin Miner?

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ASIC Bitcoin miners are essentially single-function computers with many of the same components. They are huge, cumbersome, noisy boxes which have one purpose and one purpose only – to mine Bitcoin. But what is inside an ASIC miner, and what does each bit do? We open up your average Bitmain Antminer and take a look.



The PCB is the brains behind the ASIC miner. It connects to the two hashing boards via data cables and also features the ethernet port, power/reset buttons, and a small speaker for emitting warning sounds.

All operational changes you make are translated on the PCB and sent to the hashing boards to carry out.


Hashing Boards


The hashing boards are two big circuit boards that carry out the grunt work of solving the computations needed to keep the Bitcoin blockchain chugging along. They are connected to the PCB and also receive power directly from the power supply.

The hashing boards are where the ASIC chips are housed. These are the specific parts of the miner that carry out the calculations, and there are often multiples on one board – the above example shows 16 per board. Just like a regular CPU they get extremely hot, and so they need constant cooling.



A hardworking miner generates colossal heat, and so it requires a great deal of cooling. Just like regular computers, the majority utilize air cooling, which means employing heatsinks and fans.

Heatsinks take up the majority of the real estate of your average ASIC miner. They are big blocks of aluminium designed in such a way as to draw heat from the chips, often screwed to both sides. Without these the chips would overheat and burn out, but the requirements needed to keep them cool enough to operate make for one chunky unit.



Fans are located at either end of the miner to ensure a consistent air flow direction – one fan sucks cool air in from outside, the other draws out the warm air from inside the miner. These fans often work at full speed, with their noise output reaching around 75-90 decibels, around the same as a freight train passing by 100 feet away. Now consider hundreds of these freight trains driving by at the same time in an echoey warehouse and you realize why operators have to wear ear protectors

More recent ASIC miners, such as those used by Layer1, have employed the use of liquid cooling, which is a more effective method of cooling the chips. However, this is a more expensive approach, which is why mining operators are seeking geographical advantages to keep their ASICs cool – from former metal mines in Germany to the frozen plains of Iceland.

ASICs Not Going Away

As you can see, ASIC miners are not complicated beasts with a multitude of intricate parts. They are a one-trick pony, compared to a GPU card which is less powerful but is more flexible in what it can mine.

ASIC miners are becoming more powerful and less energy dependent over time, which is good for the miners and the planet, and unless a new technology comes along that blows them out of the water, ASIC miners will likely still be what we’re using in 2030 to grab that sacred Bitcoin.