By this stage, you will understand how bitcoin works, and what mining means. But we need to get from theory to practice. How can you set up a bitcoin mining hardware and start generating some digital cash? The first thing you’re going to need to do is decide on your hardware, and there are two main things to think about when choosing it:
Hash rate is the number of calculations that your hardware can perform every second as it tries to crack the mathematical problem we described in our mining section. Hash rates are measured in megahashes, gigahashes, and terahashes per second (MH/sec, GH/sec, and TH/sec). The higher your hash rate (compared to the current average hash rate), the more likely you are to solve a transaction block. The bitcoin wiki’s mining hardware comparison page is a good place to go for rough information on hash rates for different hardware.
When choosing a hardware, it’s worth looking at your device’s energy consumption. All this computing power chews up electricity, and that costs money. You want to make sure that you don’t end up spending all of your money on electricity to mine coins that won’t be worth what you paid.
To work out how many hashes you’re getting for every watt of electricity that you use, divide the hash count by the number of watts.
For example, if you have a 500 GH/sec device, and it’s taking 400 watts of power, then you’re getting 1.25 GH/sec per watt. You can check your power bill or use an electricity price calculator online to find out how much that means in hard cash.
However, there’s a caveat here. In some cases, you’ll be using your computer to run the mining hardware. Your computer has its own electricity draw on top of the mining hardware, and you’ll need to factor that into your calculation.
There are three main hardware categories for bitcoin miners: GPUs, FPGAs, and ASICs. We’ll explore them in depth below.
CPU/GPU Bitcoin Mining
The least powerful category of bitcoin mining hardware is your computer itself. Theoretically, you could use your computer’s CPU to mine for bitcoins, but in practice, this is so slow by today’s standards that there isn’t any point.
You can enhance your bitcoin hash rate by adding graphics hardware to your desktop computer. Graphics cards feature graphical processing units (GPUs). These are designed for heavy mathematical lifting so they can calculate all the complex polygons needed in high-end video games. This makes them particularly good at the Secure Hash Algorithm (SHA) hashing mathematics necessary to solve transaction blocks.
One of the nice things about GPUs is that they also leave your options open. Unlike other options discussed later, these units can be used with cryptocurrencies other than bitcoin. Litecoin, for example, uses a different proof of work algorithm to bitcoin, called Scrypt. This has been optimized to be friendly to CPUs and GPUs, making them a good option for GPU miners who want to switch between different currencies.
GPU mining is largely dead these days. Bitcoin mining difficulty has accelerated so much with the release of ASIC mining power that graphics cards can’t compete.
FPGA Bitcoin Mining
A Field Programmable Gate Array (FPGA) is an integrated circuit designed to be configured after being built. This enables a mining hardware manufacturer to buy the chips in volume, and then customize them for bitcoin mining before putting them into their own equipment. Because they are customized for mining, they offer performance improvements over CPUs and GPUs. Single-chip FPGAs have been seen operating at around 750 MH/sec, although that’s at the high end. It is of course possible to put more than one chip in a box.
ASIC Bitcoin Miners
This is where the action’s really at. Application Specific Integrated Circuits (ASICs) are specifically designed to do just one thing: mine bitcoins at mind-crushing speeds, with relatively low power consumption. Because these chips have to be designed specifically for that task and then fabricated, they are expensive and time-consuming to produce – but the speeds are stunning. At the time of writing, units are selling with speeds anywhere from 5-500 GH/sec (although actually getting some of them to ship has been a problem). Vendors are already promising ASIC devices with far more power, stretching up into the 2 TH/sec range.
Before making your purchase, calculate the projected profitability of your miner, using mining profitability calculators online like this one. You can input parameters such as equipment cost, hash rate, power consumption, and the current bitcoin price to see how long it will take to pay back your investment.
One of the other key parameters here is network difficulty. This metric determines how hard it is to solve transaction blocks, and it varies according to the network hash rate. Difficulty is likely to increase substantially as ASIC devices come on the market, so it might be worth increasing this metric in the calculator to see what your return on investment will be like as more people join the game.
Once you have chosen your hardware, you’ll need to do several other things. Depending on which equipment you choose, you will need to run software to make use of it. Typically when using GPUs and FPGAs, you will need a host computer running two things: the standard bitcoin client, and the mining software.
The standard bitcoin client connects your computer to the network and enables it to interact with the bitcoin clients, forwarding transactions and keeping track of the block chain. It will take some time for it to download the entire bitcoin block chain so that it can begin. The bitcoin client effectively relays information between your miner and the bitcoin network.
The bitcoin mining software is what instructs the hardware to do the hard work, passing through transaction blocks for it to solve. There are a variety of these available, depending on your operating system. They are available for Windows, Mac OS X, and others.
You may well need mining software for your ASIC miner, too, although some newer models promise to ship with everything pre-configured, including a bitcoin address, so that all you need to do is plug it in the wall.
One smart developer even produced a mining operating system designed to run on the Raspberry Pi, a low-cost credit card-sized Linux computer designed to consume very small amounts of power. This could be used to power a USB-connected ASIC miner.
Now, you’re all set up. Good for you. But you will stand little chance of success mining bitcoins unless you work with other people, by joining a bitcoin mining pool for example.
Nowadays, the bitcoin mining industry primarily operates on a pool level rather than on an individual level. Some of the biggest bitcoin miners in the world are F2Pool, Poolin, Slush Pool and AntPool.