How to Build a Mining Rig for Ethereum Mining in 2021. Hardware, Components, and Video Cards.

How Does a Mining Farm Work? 

Video cards perform calculations according to a specific PoW algorithm that supports the whole blockchain network. When your machine participates in this process to solve cryptographic puzzles (we won’t go into details about such technicalities here), you receive a reward. Basically speaking, you can earn money using hardware since many coins are quite expensive. The most important thing here is to remember about paying electricity bills. 

A mining farm is an investment first and foremost. You invest your money in hardware (video cards, power units, motherboards, rent, electricity). The hardware earns cryptocurrencies. You, as an investor, have to wait through a period of recoupment to start getting pure profits. 

The main advantage of mining is that is acts as a source of passive income. You invest in your hardware, build and setup farms, and they, in turn, work for you earning crypto. Time cost is minimal: you only need to upkeep the equipment and conduct maintenance. 

Revenue flow from farms is relatively stable over a long enough period while you can continue doing what you are interested in or working. 

Where to buy components for farms? 

Most of hardware you can purchase or order in specialized stores. Some of rare components are easier to get from AliExpress. For example, risers for video cards or sync-power supply. 

! Avoid getting leases on hardware since you won’t be able to precisely estimate your revenue in the long term to cover monthly installments. 

Sometimes, the secondhand market of used components offers a wide variety of video cards and motherboards. Purchasing such components is risky as you can never know how long a used video card will work and how it was used before you got your hands on it.  

What is mining farm made of? 

A farm can consist of a single PC or even a single video card. However, a tiny farm like this is akin to a practical joke. A single PC with a couple of video cards is called a rig or a farm. Usually, a rig consists of 4 or more video cards up to 20 cards attached to the unit using risers, cable extenders that are compatible with PCI-e slots of motherboards. Video cards are powered by a server power unit or multiple ATX units. An OS is installed on a cheap SSD or on a USB-drive to increase load times and speed up updates. A processor is usually something simple that you would usually see in an office PC. It is recommended to use either DDR3 or DDR4 memory sticks (I don’t even consider DDR2 as they older than dinosaurs). The required memory capacity depends on the type of software and cryptocurrencies that you plan to mine. A Linux-based OS won’t require more than 4 Gb while a Windows-powered device will need at least 8Gb especially is you are planning to mine Ethereum, you will also need additional swap file space. One of the best OS in the market is definitely HiveOS, a light OS for mining with a bunch of different ways to tweak and fine-tune, detailed statistics, and, what’s more important, a stable architecture that works without any issues. 

Important things to remember when building a farm 

First and foremost, you need to think about ventilation and ensure that the room is well ventilated. If necessary, install an air conditioning unit. The best location for a farm is a basement or a garage in regions with cooler climates. 

Secondly, you must use good cabling: thick copper wires, expensive switches, failsafe systems, reinforced racks, reliable electricity routing components, and current equalizers. If you put rig at home and it is not something monstrous, using good wiring is usually enough. 

Thirdly, you need to use high-speed internet connection, preferably cable or even optic fiber using a good router. You can connect your farms using LAN-cables through switches. It is possible to get by using a 4G-modem with an additional antenna to increase the signal. Having a stable, fast ping is great when you are working in a pool. If your internet is slow some of the data will be rejected by the network effectively reducing your chances to earn a reward. 

Fourthly, use smart WiFi outlets to reboot your units when they freeze, glitch, or stop responding altogether. Adding IP video surveillance is also a good idea, add some smore detectors as well.  

How to build an Ethereum mining farm? 

Here are components for a typical mining farm: 

• Video cards; 
• A motherboard; 
• A processor; 
• Memory (RAM); 
• SSD, HDD or a USB-drive; 

• Processor cooler; 
• Risers; 
• Power units; 
• Case. 

Mining farm step-by-step guide: how to DIY 

Any PC build, as any farm, starts from a good foundation: a motherboard, processor, RAM, and storage unit.  

Motherboards for mining 

Let’s start with a motherboard for a farm. A simple motherboard won’t work for us since it will have a limited PCI-e slots for video cards. Motherboards for mining have additional power inputs to ensure stable performance from other components. 

The list of motherboards for mining farms 

The most popular and affordable option is ASRock H81 PRO BTC R2.0 LGA 1150 

• Chipset: Intel H81;  
• Socket: 1150 (4-5 generations of Intel Core i7 / i5 / i3 / Celeron); 
• RAM: dual-channel DDR3;  
• PCI-Express x1: 5;  
• PCI-Express x16: 1;  

• Price: 180 USD.  

It is good for mining using up to 6 video cards while relatively good-quality RAM and processor can be purchased on secondary market for pennies. It is not a bad option for your first farm.   

Gigabyte GA-B250-FinTech is a more serious and contemporary solution. 

• Chipset: Intel B250;  
• Socket: LGA 1151 (6-7 generation of Intel Core i7 / i5 / i3 / Celeron);  

• RAM: 4 DDR4 slots;  
• PCI-Express x1: 11;  
• PCI–Express x16: 1;  
• Price: 480 USD.  

This motherboard supports modern Intel processors, can be hooked up with up to 12 video cards allowing you to create two farms from a single unit. For so many video cards, you will need a server power unit or several good ATX units.  

• MSI H310-F PRO is also a high-end solution for a powerful farm that also supports the latest generation of processors.  
• Chipset: Intel B310;  
• Socket: LGA 1151v2 (8 generation of Intel Core i7 / i5 / i3 / Celeron);  
• RAM: 2 DDR4 slots;  
• PCI-Express x1: 12;  

• PCI–Express x16: 1;  
• Price: 790 USD. 

Motherboard Colorful C.B250A-BTC PLUS YV20 is a very specialized option for compact builds.  

• Chipset: Intel B250;  
• Socket: LGA 1151 (6-7 generation of Intel Core i7 / i5 / i3 / Celeron);  

• RAM: 1 SO-DIMM DDR4 slot;  
• PCI-Express x1: 7;  
• PCI–Express x16: 1;  
• Price: 600 USD.  

Colorful C.B250A-BTC PLUS YV20 won’t work for any miner as it was conceived for compact builds. Video cards are installed directly in PCI–e slots without using risers. 6-pin power supply for video cards will suffice for most farms. 

• Asus B250 Mining Expert is a great build for up to 19 video cards!  
• Chipset: Intel B250;  
• Socket: LGA 1151 (6-7 generation of Intel Core i7 / i5 / i3 / Celeron);  
• RAM: 2 DDR4 slots;  
• PCI-Express x1: 18;  

• PCI–Express x16: 1;  
• Price: 900 USD.  

This particular piece of hardware is quite hard to find as it is one of the most demanded motherboards. There is also a concern with stability when 19 video cards work together. Such farms require dramatic investments in high-end components, especially power units. 

Risers for farms. 

To connect all video cards with a motherboard, you will need to use specialized cable extenders called risers. Usually the length of an extender is under 70cm to avoid data losses. Risers are connected to the PCI-e slots in the motherboard and video cards are installed in PCI-e x16 slots on the riser plate.  

Additional power supply is routed to the riser directly from the power unit using 12V current. Different versions and models of these devices exist in the market but most differ in connectors only. Some of the best and most stable are 006 ver. risers but they use Molex with SATA adapters. However, it is a good idea to search for 6-pin risers since it is much easier to use them for owners of server power units.  

Don’t forget that different bridges on power lines can be negatively affected by electric currents. Risers are usually connected on the rail of the case above the motherboard. 

Power units for motherboards.  

Which power unit is the best for your farm? First and foremost, you need to decide how many video cards will be used in the build and calculate their combined power consumption and only then start searching for a suitable PSU.  

Here are some of the most important criteria for a PSU:  

• Wattage; 
• Modularity (variety of slot types);  
• Various failsafe options (protection from short circuits, overloads, overheating, undervoltage);  
• Energy performance certificate. 

There are two types of power units: 

1. Server; 

1. ATX. 

Server power units have higher tolerance, higher wattage, and more 6+2 pin slots. As a rule, one such power unit is enough to power any farm using from 6 to 20 video cards. However, the prices on such high-end power units are very sky-high. Sadly, you have to pay for convenience and reliability. 

On the other hand, server power units have their own disadvantages. Some older models have to be modified to be used with ATX slots in motherboards and may need additional tinkering. Contemporary power units can be found in specialized online stores. 

Regular ATX units for PCs are quite convenient as well since you can use them to power several video cards in a small farm. If you have powerful video cards, you may need to use two or more power units. This type of PSU’s is also cheaper. 

How to connect two power units to a single farm? 

To connect two power units to a single farm, you need to choose cables according to expected load to determine which power unit will supply the motherboard and the hard rive (but who uses hard drives in 2021? SSDs and USBs are way better!). If you have, for example, 6 video cards and two power units then three cables from one unit must go to three video cards and their risers while other three video cards must be connected to another power unit and also to three their risers.  

To ensure that the second power unit is working, you will need to circuit green and black cabling on the 24-pin ATX slot, you can use a piece of wire to do so. 

However, there are also specialized sync modules that ease your life as a miner. 

Types of sync-modules for PSU. 

• Sync modules that use 12V-standby closed circuit in different power units (ATX 20+4pin cable) are the cheapest and most compact but with the lowest safety level compared to sync modules that separate different circuits with optocouplers or relays.  
• Sync modules that turn on connected power units when 12V current is detected in the main power unit with a mechanical relay. 
• Sync modules that turn on connected power units when 12V current is detected in the main power unit with an optocoupler. 

To connect sync modules with relays and optocouplers, you can use one of SATA cables to establish connection with the sync module. In this sync module, a 20+4pin cable from the secondary unit is inserted. It can be used to power video cards and risers that require additional power supply. 

How to calculate the requirements for a power unit for mining? 

To calculate the wattage required, you need to use the following principles: 

Use maximum power consumption numbers for any given video card (TDP stands for Thermal Design Power or Total Drawn Power). This is wattage that GPU draws in when operating at 100% capacity. TDP values for the most productive video cards in the market are in the table below. 

You need to include 150W for the base components such as processor, memory, motherboard, and HDD/SSD. 

When calculating the wattage make sure to consider 20%-25% reserve. Basically, you need to multiply the estimated rig’s power consumption by at least 1.25. It will ensure that you rig is always sufficiently powered and power units perform with the highest efficiency at 70%-80% load meaning that you will save some money on electricity due to more efficient usage of power. 

For example, a rig with 6 Nvidia 1080Ti TDP will consume 250×6=1500W. Additionally, we need 150W for our motherboard and other components. Since we need at least 20% reserve, we need to use a PSU (or two) with at least (1500+150)x1.25=2063W. 

It is always better to purchase PSU with golden, platinum, or titanium energy performance certificates (listed from worst to best). The price difference will pay for itself within a year due to saved electricity wasted on inefficient performance. The best EPC power units also use high-end electronics and failsafe mechanisms ensuring overall safety.  

The list of video cards for Ethereum mining: 

• AMD Rx 470 8 gb — 28-30 Mh/s (100 W)  
• AMD Rx 480 8 gb — 30-31 Mh/s (120 W)  

• AMD Rx 570 8 gb — 28-30 Mh/s (100 W)  
• AMD Rx 580 8 gb — 30-31 Mh/s (120 W)  
• AMD Rx 5700 XT 8gb — 55 Mh/s (200 W)  
• Nvidia GTX 1080 8GB — 38 Mh/s (180 W)  
• Nvidia GTX 1060 6GB — 16 Mh/s (80 W)  

• Nvidia GTX 1070 8GB — 31 Mh/s (150 W)  
• Nvidia GTX 1660 6GB — 24 Mh/s (100 W)  
• Nvidia RTX 2070 8GB — 38 Mh/s (180 W) 

All of the GPUs above have high values of profits and ROI but what’s more important is that they are quite good at mining other cryptocurrencies. Video cards by AMD Radeon RX (400 and above) have to be fine-tuned and flashed by switching timinigs in the BIOS and also require lowering the voltage. After such manipulations, the different will be most apparent when mining with Dagger-Hashimoto algorithm.  

Which video cards are most used for mining in 2021? 

You can easily find out the preferences of miners in regards to video cards. To determine which cards are the hottest in the community, you can use the HiveOS platform where you will find the data in the statistics page. 

More than 50% of all AMD cards are Radeon RX580 8Gb and RX570 4Gb. The third place is taken by a simple RX580 while the fourth place is occupied by RX470 with RX570 8Gb closing the TOP5 list. 

Nvidia’s situation is quite different: the top spots are all occupied by cheaper options. There are both GTX 1060 and 1070. The last card to cross the 10% mark is GeForce GTX 1080 Ti 11Gb. 

On the right, you will see the ratings for ASIC-units.  

The best video card for mining 

Since BTC price skyrocketed in 2021 beating its own projected record by a factor of two, the interest towards mining has risen quite considerably which led to shortages of video cards all across the globe as well as many other components. 

Some of the most affordable video cards for a farm are undeniably RX 580 8Gb and GTX 1080 which can be found both in the stores and on the secondary market. They are also quite effective in regards to energy efficiency and profitability. 

Which cards are most relevant for mining purposes? Well, AMD RX5700, RX5700 XT, RTX 2070, and 3000-series from Nvidia as well as RTX3080 reach the highest hash rates when mining Ethereum. 

Yes, the best video card for Ethereum mining is RTX3080. Its has rate can reach 90 MH/s at 320W TDP. 

It is the most profitable and powerful GPU for a farm. However, there is a nuance: it is quite hard to find it in stores just like the latest generation of AMD RX 6000 cards. 

With the current price of ETH hovering over $1200, Nvidia RTX3080 will earn at least $7.5 per day!  

The price of the video card is about $1600 but if the prices of cryptocurrencies will remain at this level and the difficulty of the network won’t increase dramatically, an RTX3080 can be paid off in 250 days! Even if the profitability will drop by a factor of two, the period of recouping will be less than one and a half year! 

The price of an average mining farm 

• A mining farm with 8 Nvidia RTX3080 cards will be about $17000. 
• A mining farm with 6 AMD RX5700 XT will be about $8200. 

• A mining farm with 6 RX 580 8 GB will cost you around $5600. 

How to calculate the profitability of a farm?  

To determine how much a farm can earn, I recommend you using WhatToMine.com calculator.  

You will need to input the number of video cards in the farm, how much you pay for electricity, and energy consumption (will be calculated automatically). 

The calculator will give you a list of suitable coins that will be most profitable to mine at the moment and an estimation of how much you will earn with your current computational power. 

Operating systems for mining. 

To turn your video cards into mining monsters, you need to not only build all components into a rig but also install suitable software on the drive. 

Here is the list of OS for mining: 

• Windows 10;  
• HiveOS;  

• RaveOS;  
• NicehashOS.  

Windows is best suited for testing and flashing video cards or to use your PC to mine some coins when you are asleep. Just don’t forget to install special drivers for mining if you are using AMD cards. 

NicehashOS is built on the light Linux distributive. The main advantages of this OS is that it has benchmark feature for your video cards to determine the most profitable algorithm for mining. All earnings are transferred to your account in BTC. There are two downsides: you don’t have any ways to tweak your hardware and you don’t see which coins your hardware is mining. It is a better option for newcomers. 

HiveOS and RaveOS are also built on the base of a light Linux distributive. They are nearly identical in terms of functionality and even in terms of interface. You have a bunch of settings for your farms to work with, you can fine tune each of your video cards, and you can also reconfigure your miner. It is the best option for experienced users. 

These OS automatically determine the model and manufacturer of video cards, install suitable drivers, and work without many issues. One of the reasons for increased stability is the watchdog function that will reboot the miner and the system if a video card glitches out. 

Under Windows, farms may freeze and glitch out of nowhere and stop working after a day, a week, or a month. Linux is usually much more stable and reliable. 

The best OS for mining in 2021 

Without a doubt, it is impossible to firmly state that one OS is better than everything else. The choice of the most efficient system is a personal matter with each miner finding something specific in each build. However, when taking into account statistics and my personal experience of working with different farms, HiveOS definitely takes the crown in terms of convenience, stability, and reliability. 

Wallet for mining. 

To start mining Ethereum, you need to create a cryptocurrency wallet. We recommend you using Binance, one of the best cryptocurrency exchanges in the world. 

The main takeaway 

Hopefully, this long-read about building Ethereum mining farms was useful to you. I plan to update it with relevant information in the future. 

I want to believe that mining profitability will stay high for the foreseeable future so that everyone could enter the world of crypto and start earning money after building their first rig. Judging by my personal experience, many of my friends and acquaintances managed to turn mining into a good investment enterprise. Some started mining using a single video card on their gaming PC, then grew to the level of a garage miner and continued growing. 

Nowadays, finding a good video card for a farm at a reasonable price is quite hard with some models completely gone from the shelves. In the beginning of February, I saw someone trying to sell an RTX 3070Ti for over $10000 on e-Bay. Such things can shock you! I recommend you to learn about a new way to farming without any video cards and farms — cloud mining. It is relevant as never before. It’s true: why would you buy video cards for sky-high prices when you can rent these machines and mine BTC and ETH that keep growing!