GPU mining refers to the use of a graphics processing unit (GPU) to mine cryptocurrencies such as Bitcoin, Ethereum, and others. Instead of using CPUs, GPUs are more efficient at processing the complex mathematical calculations required for mining. A GPU mining rig is a dedicated computer system built specifically for mining cryptocurrencies using one or more GPUs.

Why Use a GPU for Mining?

GPUs were originally designed for graphics intensive tasks like gaming and video editing. Their highly parallel architecture makes them efficient at handling multiple tasks simultaneously. This makes them ideal for mining cryptocurrencies which rely on performing repetitive cryptographic hash calculations.

Some key advantages of GPU mining over CPU mining include:

• Higher hash rates: GPUs can calculate hash functions much faster than CPUs which results in higher mining output. Top end GPUs can hash at rates 100x faster than CPUs.
• More parallel processing: GPUs have thousands of small cores optimized for parallel processing whereas CPUs only have a few large cores. This parallelism makes GPUs better suited for mining.
• Higher efficiency: GPUs require less energy per unit of calculation compared to CPUs which makes them more energy efficient for mining.
• Cost effective: GPUs are readily available as consumer products and cost effective when assembled into a mining rig. CPUs designed for mining can be expensive.

Choosing GPUs for Mining

When building a GPU mining rig, the most important factor is choosing the right GPU model. Things to consider when selecting GPUs include:

• Hash rate: The higher the hash rate or computing power, the better. Top models from AMD and Nvidia offer the best performance.
• Cost: The GPU price should be affordable for the hash rate performance. Avoid older used GPUs which may be prone to faults.
• Power efficiency: Choose GPUs with lower power draw and better energy efficiency for mining. This reduces the electricity costs.
• Memory: Having more GPU memory (RAM) allows mining of cryptocurrencies on memory intensive algorithms. At least 8GB RAM is recommended.
• Availability: Select GPUs that are readily available for purchase new rather than used. This reduces the chances of faulty GPU units.

Popular GPUs suitable for mining include:

• AMD Radeon RX 580, RX 5700/5700XT
• Nvidia GTX 1060/1070/1080/1080Ti/1660/1660Ti
• AMD Vega 56/64

These offer a good combination of hash rate performance, efficiency and cost. Multiple GPUs can be used in a mining rig for increased mining power.

Mining Rig Hardware Components

In addition to GPUs, a mining rig requires several other standard computer components to operate. These include:

Motherboard - This serves as the base to connect the GPUs and other components. A motherboard with multiple PCIe slots allows installing more GPUs.

CPU - A basic CPU is needed to boot and run the mining operating system. An AMD Ryzen or Intel Celeron/Pentium processor is sufficient.

RAM - 8GB or more of DDR4 RAM is recommended for mining rigs running multiple GPUs. Having adequate RAM reduces slowdowns and crashes.

Storage - A 128GB SSD boot drive is enough for installing the operating system and mining software. An optional 1TB or more HDD can store the blockchain ledger.

Power Supply - A high wattage 80 Plus Gold certified PSU is recommended to provide stable power for the GPUs. Power capacity should exceed the total GPU power draw.

Riser Cables - Special PCIe riser adapter cables allow installing GPUs vertically and spacing them out to improve airflow.

Case - An open air mining rig frame or a well vented PC case is ideal for housing and cooling multiple GPUs.

Operating System - Most mining software runs on Linux distros like HiveOS, RaveOS, Ubuntu, etc. But Windows 10 can also be used.

Building & Configuring the Mining Rig

Once the components are ready, assemble the mining rig by installing the GPUs, connectors and other parts in the case. Ensure adequate spacing between GPUs for ventilation.

Install the mining operating system on the boot drive. Enable internet access to download blockchain data and mining pools. Install any required drivers like AMD/Nvidia GPU drivers.
Configure the mining software settings as per the selected cryptocurrency and mining pool. Input your wallet address to receive mined coins. Enable overclocking to maximize GPU mining hash rates.

Power up the mining rig and launch the mining software to initiate mining using the GPUs. Monitor mining status and temperatures to ensure stable mining operations.

Typical maintenance includes periodically cleaning dust from GPU fans and heatsinks. Also monitor for any GPU failures which may require replacement of faulty units.

Optimizing the GPU Mining Rig

To maximize mining profits, optimize the mining rig for best performance:

• Enable GPU overclocking to increase hash rates but maintain system stability.
• Adjust GPU undervolting to reduce power draw and lower temperatures.
• Use efficient GPU riser cables and spaced out rig builds for better cooling.
• Keep GPU drivers and mining software updated to take advantage of optimizations.
• Configure pools with lower fees and server locations closer to your location.
• Monitor mining status and payouts to identify and fix any issues.
• Consider dual mining alternate cryptocurrencies to boost profits.
• Eventually upgrade to newer and higher performing GPUs.

Safety Considerations

Mining rigs with multiple GPUs can draw a lot of power and require safety precautions:

• Use a 220V AC power connection with sufficient amperage capacity.
• Install a dedicated circuit breaker if needed to avoid tripping other circuits.
• Use a power strip with surge protection.
• Do not overload extension cords and avoid using hazardous temporary wiring.
• Keep rigs in well ventilated rooms to dissipate heat buildup.
• Monitor temperatures and maintain adequate cooling to avoid GPU overheating.
• Shut down components safely before building and handling to avoid electric shock.
• Ensure cables are properly secured to avoid tripping or equipment damage.
• Keep rigs running stably to avoid crashes, corrupt blocks and risks of damaging GPUs.
• Adhere to all electrical safety standards and building codes for mining rig installations.

Mining Cryptocurrencies with GPU Rigs

GPU mining expanded from Bitcoin to other cryptocurrencies like Ethereum, Monero, ZCash and Ravencoin which are minable on consumer GPUs.

• Ethereum is likely the most popular for GPU mining due to its coin value and mining difficulty stability.
• Monero favors home miners using CPUs and GPUs due to its cryptonight algorithm.
• ZCash, Ravencoin and Conflux also offer good profits for mining on GPU rigs.
• Mine the most profitable coins based on market value, mining difficulty, algorithms and exchange trading options.
• Dual mine alternate cryptocurrencies to maximize profits from the GPU hardware.
• Join a suitable mining pool with lower fees, high uptime and reliable payouts.
• Use platforms like NiceHash which switch to mining the most profitable coins automatically.

Over time, profits for GPU mining vary based on cryptocurrency price trends, mining difficulty, competition and equipment. By optimizing GPU rigs and selecting profitable coins to mine, hobbyist miners can still benefit from home based GPU mining.

GPU mining allows leveraging consumer graphics cards to profitably mine cryptocurrencies. With the right mining rig components and optimization, GPUs provide a cost effective method for mining a variety of cryptos. Carefully selected GPUs, adequate cooling, updated software and fine tuning can help maximize mining returns over time as the crypto markets evolve.