Bitcoin mining is an interesting way of trying to make a few bitcoin tokens on the side, but it also serves a very important purpose in maintaining and keeping the bitcoin blockchain secure.
Unlike regular fiat currencies (such as US dollars or euros), bitcoin assets are not controlled by a central government or bank, and new bitcoin (BTC) cannot be printed and issued like paper money. Instead, bitcoin tokens are introduced into the market via a process known as “mining”. BTC are awarded to the miners who have solved the math problems necessary to verify bitcoin transactions.
What is mining?
Whenever a transaction is made in bitcoin, a record of it is made on a block containing other recent transactions, like a page in a ledger. Once the block is full, bitcoin miners compete against each other to verify and validate the block and all its transactions by solving a complex cryptographic problem. The first miner to accomplish this is awarded a set amount of bitcoin, based on the mining difficulty at the time. The verified block is then added to the blockchain, a history of all blocks verified since the beginning of bitcoin, and transmitted to all users of bitcoin so that they can have the latest blockchain.
Proof of work
At the heart of bitcoin mining lies a hard, mathematical problem. The goal is to ensure that the process of adding a new block to the blockchain requires a lot of work. That helps to ensure that any hacker tampering with the transactions needs not only to mess with the transactions but also win the “race” of bitcoin mining.
Evolution of the mining computer
- CPU mining. In the early days of bitcoin, mining difficulty was low and not a lot of miners were competing for blocks and rewards. This made it worthwhile to use your computer’s own central processing unit (CPU) to mine bitcoin. However, that approach was soon replaced by GPU mining.
- GPU mining. A graphics processing unit (GPU) is a powerful processor whose sole purpose is to assist your computer’s graphics card in rendering 3D graphics. GPUs are not built for executive decisions (like CPUs) but to be very good labourers, hence GPUs are able to execute over 800 times more instructions in the same amount of time as a CPU. Mining is a repetitive process that does not require any intelligent decisions, leading to GPUs replacing CPUs in the mining world.
- FPGA mining. Next came mining with field-programmable gate arrays (FPGAs). These greatly outperformed GPUs and CPUs in the mining process as FPGAs are processors that can be programmed to execute specific instructions and only those instructions (instead of being repurposed for mining, like GPUs were).
- ASIC mining. Similar to FPGAs, application-specific integrated circuits are chips designed for a specific purpose, in our case mining bitcoin, and nothing else. ASICs for bitcoin were introduced in 2013 and, as of November 2017, they are the best processors available for mining bitcoin and they outperform FPGAs in power consumption.
- Mining pools. To offset the difficulty of mining a block, miners started organising in pools or cloud mining networks. Whenever a miner in one of these pools solves a block, the reward is shared with everyone in the pool in a ratio representative of how much work you put into the pool (even though you personally never solved the puzzle).
- Cloud mining. Clouds offer prospective miners the ability to purchase mining rigs in a remote data centre location. There are many obvious advantages, the most obvious being: no electricity costs, no excess heat and nothing to sell when you decide to hang up your virtual pickaxe.
Are people still making money mining bitcoin?
Making money mining bitcoin is much more difficult today. The following are some of the issues contributing to this difficulty:
- Hardware prices. The days of mining using a standard CPU or graphic card are gone. As more people have begun mining, the difficulty of solving the puzzles has increased. ASIC microchips were developed to process the computations faster and have become necessary to succeed at mining today. These chips can cost $3,000 or more and are guaranteed to further increase in cost with each improvement and update.
- Rise in corporate miners. Hobby miners must now compete with for-profits — and their bigger, better machines — when mining to make a buck.
- Puzzle difficulty. Bitcoin’s protocol adjusts the computational difficulty of the puzzles to finish a block every 2,016 blocks. The more computational power put toward mining, the more difficult the puzzle.
- Power costs. Running mining equipment all day long can consume a lot of electricity, which you’ll need to weigh up against any mining profits generated.
The rising costs of mining effectively and competing against large mining pools have made it harder for the hobbyist to profit on mining bitcoin.
It’s virtually impossible to mine enough bitcoin to recoup your initial cost of equipment and electricity. But if you’re not so concerned about making a buck, you could have fun panning for this cool currency.