Introduction: Litecoin & Scrypt Mining Rig - Get in on Bitcoin With GPUs
You may have heard of Bitcoin. Maybe you have heard of Litecoin or Dogecoin. These are cryptocurrencies, a distributed, decentralized, secure set of technologies making their appearance as coins. Cryptocurrency technologies can be used to store data with their transactions, and many applications of the technology are sure to develop in the near future that are far beyond what is currently advertised as a replacement for traditional money transactions.
Regardless of reason for interest in cryptocurrency, the hardware is pretty much the same. It is divided among a few different hardware platforms that have come about during the evolution of the technology.
CPU aka the main chip on the computer motherboard that does most all of the processing - Bitcoin began here. There are a few coins that are written in software that continue to run only on CPU.
GPU aka the graphics card that typically is used to display games - High-end graphics cards lend well to heavy processing and cryptography. Bitcoin has since moved past graphics cards in processing power, but Litecoin and many other variations run on GPUs using a hashing algorithm call Scrypt. There is a great effort in the coin community to keep some coins on GPUs where a person can purchase off the shelf graphics cards and be part of cryptocurrency.
ASICs aka Application Specific Integrated Circuits - These are very specialized circuits designed for speed and efficiency. Bitcoin mining is all on ASICs now and new versions of ASICs are appearing for Litecoin and other coins. ASICs have no other purpose but to mine coins with the same hashing algorithm of Bitcoin which is SHA256 and have little resale value or usefulness once time has passed and the speed of new technology has replaced them.
This article is about building is a GPU-based rig that can be used to mine Litecoin and similar coins that use Scrypt and algorithms similar to Scrypt such as Scrypt-N. The hardware is off-the-shelf and can be used for other purposes or sold if one should decide to re-purpose the investment.
You won't be mining Bitcoin on this machine, but instead Alt-Coins. You can then trade them on the exchanges online for Bitcoin or even to dollars and euros.
Step 1: Planning
Computers require power to operate the CPU, move data in and out of memory and disk, and perform functions such as communicating over a network connection. Graphics cards are require power to display images on screens. When graphics cards display greater detail or more frames per second such as in high end games, the processing requires correspondingly more power and generates heat. High-end graphics cards require quite a bit of power when running games at high detail and fast speeds. Similar to running a game at maximum settings, running cryptocurrency hashing demands a lot from the graphics cards, pulling their maximum power and generating a lot of heat.
Planning a mining rig is not just about how many coins it can create in a day, but about energy. A typical wall outlet is can supply only a certain amount of power safely. Be warned that these high end computers can trip breakers and be a danger due to the amount of power they consume. You are responsible for running them just as if they were you own homemade space-heater.
Step 2: Power Supply
A computer with motherboard, RAM, and hard drive may perhaps consume 50 to 150 watts of power sitting idle or doing simple day-to-day stuff. Each graphics card might add anywhere from 50 to 300 or more watts of power to the total demand at the electric outlet.
Planning a mining rig is about a balance of power and heat. You want the rig to run fast, but not too hot. You want a lot of power but not too much to be dangerous. One person may prefer a rig design to have 3 or 4 extremely high end card such as the AMD R9 290 which draw over 300 watts each. A different person might prefer to have 4 to 6 still very high end cards such has AMD R9 270 wich each draw 150 watts. Cards in different series and from different manufacturers and ever different revisions have very different results in how much hashing they can do for a certain amount of power and heat. Additionally, there are many people on internet forums that offer advice as to "undervolt" cards to run cooler at a lower voltage and increase efficiency. That is beyond the scope of the article, but now you know to search for it.
Our system is using a power supply that is just enough for the cards that are chosen. You MUST make sure to size a power supply so that it can handle the load of all components.
Step 3: Build List
The build list is that of a typical tower PC except that there is not a typical case because of the number of graphics cards and heat from those cards. In fact, many DIY and home build rigs are done in milk crates with zip ties. On ebay and other sites, however, there are wooden and metal specialty mining frames that can be purchased.
Our setup is going to be the following:
- Motherboard - $70-$150
$65 gets a BIOSTAR Hi-Fi H81S2 LGA 1150 Intel H81 SATA 6Gb/s USB 3.0 ATX Intel Motherboard that has 6 PCIe slots. We're only going to use 5 but it's nice to have options. http://www.newegg.com/Product/Product.aspx?Item=N82E16813138394
- CPU - $50-$70
$70 gets an Intel Pentium G3220 Haswell 3.0GHz LGA 1150 54W Dual-Core Desktop Processor Intel HD Graphics BX80646G3220 that works very well and matches with motherboards in a reasonable price range. http://www.newegg.com/Product/Product.aspx?Item=N82E16819116950
- Graphics Cards (GPU) - Qty 5 - $225-$250 each
The card used in this setup is an AMD R9 270x. At the time of purchase it was on sale or else a 270 would have been the choice. The "x" does not add much for miners. The 270 non-X actually may be in many cases more power efficient by a slight margin, and lower cost of power means a better bottom line profit. The config files supplied later in the article are for the 270x.
$260 ASUS R9270X-DC2T-2GD5 Radeon R9 270X 2GB 256-bit GDDR5 PCI Express 3.0 CrossFireX Support Video Card http://www.newegg.com/Product/Product.aspx?Item=N82E16814121802
$220 ASUS R9270-DC2OC-2GD5 Radeon R9 270 2GB 256-bit GDDR5 PCI Express 3.0 HDCP Ready CrossFireX Support Video Card
- RAM - $45
4GB is a good amount to have for your mining software to run smoothly. It would be the minimum in order to run Windows and works well for Linux and distros such as BAMT. This setup uses G.SKILL Ripjaws X Series 4GB 240-Pin DDR3 SDRAM DDR3 1866 (PC3 14900) Desktop Memory Model F3-14900CL9S-4GBXL from Newegg for $45 http://www.newegg.com/Product/Product.aspx?Item=N82E16820231720
- 1x to 16x Powered Riser Cables - Qty 5 - $50-$150
$10 x 5 - These are to connect the 6 graphics cards to the motherboard and allow spacing between cards for heat dissipation. Powered risers are necessary when building a rig with this many GPU’s. The 1x male end of the rise1r cable plugs into either the 1x or 16x slot on the motherboard, and the 16x slot on the cable is where you plug the graphics card into. Buy these when ordering the case from http://woodyswoodenrigs.com/ and save some time. Otherwise, you can find these on eBay, NewEgg, and Amazon. Some nicer ones (over $30 each) connect with USB cables and can extend 40 inches instead of just using ribbon cable limited to approximately 6-8 inches.
- Power Supply - $150-$250
The following power supply is used in the specified mining rig but is not in stock at NewEgg as of the time of writing. Measured by a Kill-A-Watt meter, total draw at the wall is 920 watts. A power supply is able to provide the rated output at a corresponding efficiency rating. Platinum, Gold, and Bronze are different ratings.
$150 CORSAIR RM Series RM850 850W ATX12V v2.31 and EPS 2.92 80 PLUS GOLD Certified Full Modular Active PFC Power Supply http://www.newegg.com/Product/Product.aspx?Item=N...
Look for a power supply that can easily meet the needs of the configuration. In this setup, a good 1000w or 1300w PSU would be ample power and have better efficiency though it may cost a bit more like $200 or $250.
- Case - $60
Milk crate = $5 with some zip ties. Not exactly pretty, but it's simple.
$40-60 plus s&h - I would suggest searching eBay for "wooden mining rig" and you will find some variations on the design that was used here. The wooden setup we used was from http://woodyswoodenrigs.com/ and they also sell powered riser cables for $7.
- Operating System - $0 plus $10 USB stick, 2GB+
Windows is an option, but this guide will suggest the use of BAMT. It runs on a USB stick of at least 2GB in size.
- Network Connection - $25-$50 Netgear WNCE2001
Motherboards typically have ethernet on board, but sometimes it's nice to go wireless. Netgear makes a nice product that is not well known but is perfect for what we are doing. If you purchase one from eBay that doesn't have instruction, go to Netgear's site to find how to set it up. These are great and remove any need for fiddling around with wireless drivers in the operating system.
- Monitor, Mouse, Keyboard - n/a
This is a headless server. That means we don't plan on needing anything but a network connection to control it. You may choose at some point to borrow a monitor and keyboard temporarily to set up the BIOS so that the computer starts up automatically after power is applied or after a power outage.
Step 4: Purchasing
Components can be purchased from nearly anywhere, but consider the return policy when making your decision on where to buy them. Graphics cards are under full load when mining. Some retailers and manufacturers are more or less friendly than others with warranties. Internet searches and forums show that many people like to buy from Newegg. Amazon is also a favorite. Both have many customer reviews for assistance in your purchasing decisions.
Step 5: Operating System - BAMT
BAMT is a USB-bootable linux distro designed specifically for mining.
Litecoin BAMT is a fork of the original BAMT project that supports scrypt mining and has been tested with Litecoin and other scrypt coins.
Here is a forum where you can download the software and find a great deal of help if things don't go as hoped for.
This guide assumes your personal pc runs a version of windows and you have a lan network that both your pc and the miner will be connected to.
Download BAMT from the link above.
Also download http://sourceforge.net/projects/win32diskimager/
Use the disk image program to write BAMT to a 2GB or greater USB stick. Understand that anything on that USB stick will get wiped out.
Many people use BAMT and the forums at that link will provide a great deal of support if necessary.
Step 6: Assembly
- Un-package it all
Keep your boxes and your receipts until you are sure everything is installed, fits well, and is working well. Also, having those boxes lets you sell off the items someday if you choose to.
- Build / assemble custom open air mining case
The wooded rigs from Woody's as specified in the build list are nice but please get a bottle of yellow wood glue and put glue at all joints. They kit comes with small nails that are barely enough to hold it together and the wood glue will make it a lot more secure. If you plan to move the unit around a lot, consider using screws so that your very expensive investment does not come apart when handled.
- Place motherboard in custom open air mining rig case and connect motherboard PSU connector (leaving PSU unplugged from the wall of course)
Connect the heavy PSU cables now since they are less forgiving in how they can be routed and placed. The wooden rigs from Woody's come with small nylon spacers to hold the motherboard away from the wood frame. Those same spacers could be found at a hardware store if you are building your own wooden frame.
- Plug in power switch
The motherboard in the build list does not have an on-board power switch. The motherboard manual will show where a power switch is plugged in. These switches have a minimal cost and many switches can be adapted with some wire and the right female connectors if one is not purchased.
- Install processor and RAM on motherboard
This is typical for all PC builds. Be careful with the pins on the processor chip as they bend easily. Be careful with the thermal paste as it's important for a good thermal connection to the heat sink.
- Plug in all riser cables
You may opt to do this after mounting the GPUs, depending on if you can get your hands in small spaces.
- Connect all GPUs to riser cables and fasten them to custom case.
You might need to experiment for optimal spacing to keep the cards cool, but having the prescribed 5 cards evenly spaced on one of Woody's rigs seems to work very well.
- Plug in additonal GPU power cables
GPUs come with adapters and so do the power supplies. Between both of those packages, find the right connectors and any necessary adapters that will provide power from the PSU to the GPU cards. Powered risers are only one source of power to the cards. GPUs will have 1 or 2 plugs of 6 pins that deliver the remaining power that they need to run at full throttle. Some 270 cards only have one plug as they require less power. Most other cards over 150 watts will require both of their 2 plugs to be powered.
- Plug in the network cable
Or plug in and power on the Netgear WNCE2001 if you chose that wireless option
- Plug in USB stick with BAMT already installed
- Plug in all power supply connections
- Connect mouse, monitor and keyboard if being used
Step 7: Power On
Once all the connections are checked, turn it on. Some motherboard have an on-board power button which is a new development. Others still require a switch that connects two terminals as described in the motherboard instruction manual.
If you plugged in to the network, the machine should boot into BAMT and the operating system will use DHCP to get an IP address on your network.
What's the IP address? The experts among us can scan the network for a new machine but the rest of us aren't typically using those types of tools.
There is a way to figure this out without having to plug in a monitor, mouse, and keyboard and without the need to super geek tools. Home routers provide IP addresses to machines connecting to the network. If you can log in to your router, a new machine should have appeared in the DCHP client list. Different brands of home routers have interfaces and menus that present this their own way so that may require an internet search for help on a particular model.
Step 8: Configuration - Remote Desktop Connection
BAMT typically works well and at this point the configuration will continue with screen shots using remote operation and no mouse, keyboard, or screen.
*** Should you need them go ahead and plug everything in to do such things as configure the BIOS of your motherboard so that it automatically turns on when power is applied, which is good if you lose power and want the machine to restart and always be on.
Our machine has the IP address of 192.168.1.93
More advanced users may wish to use a SSH tool to connect such as Putty.
For the rest of us open a remote desktop connection.
BAMT default user name is user and password is live
Step 9: Configuration - Root Password
We want to set the password for root.
From the menu open a terminal window.
Type "sudo passwd"
and set the pw to something not guessable
And for the user password type "passwd" and set the that password to something DIFFERENT from the root password.
To make sure all went well, log out and reconnect as each user name.
Step 10: Configuration - File Manager
BAMT comes with a standard mining configuration that is generic and needs to be changed.
More advanced users can use SSH and do things all on the keyboard or connect using a tool such as FileZilla and synchronize files.
For the rest of us, open remote desktop and log on to the machine as root.
From the menu find and open file manager.
Step 11: Mining Config File - Mining Pools
The config file holds the information as to what mining target to connect to. There are a number of ways to provide this information, but this way is simple and easy for getting started. Remote management tools like CGRemote will allow control over many mining rigs and can make managing a number of these servers much easier.
Mining pools are a completely different topic and one suggestion is to spend some time understanding where your miners are going to be pointing their power at. Search the internet and look on the forums to research mining pools. Some pools are specific to a coin, and some pools exist that switch between coins in an attempt to mine the most valuable coin at a given time.
When you have the information from the mining pool, replace the generic information that is in the config file with your own information. By default, listing multiple pools in this section allows for failover so if a pool is offline then the mining software will switch to a backup pools lower in the list.
Step 12: Mining Config File - GPU Parameters
Each series and brand of graphics cards can be optimized using parameters in the config file. In the mining config file are all the parameters that the BAMT mining software needs in order to optimize the GPU and the connection to the mining target.
Shown are settings that can be used for the ASUS R9 270X graphics card with a few tweaks to some other settings so that the software connects to a pool and looks for new instructions more often.
This section is very much determined by the brand, model, and even revision of each graphics card. The default settings may or may not work, and these settings may not be appropriate, so do some research for the particular card that is installed. Search the internet and forums for the card name or model and "scrypt" and you'll likely find a need to filter through all the many people making suggestions from their own experience.
Step 13: Mining
BAMT includes a web server that has a rather nice display of status and activity. Connect to it using your favorite web browser. In the case of our demo connect to http://192.168.1.93
The machine should be mining. If you don't see it accepting shares, the first place that would be of great help is the BAMT forums. The software typically works very well out of the box, so good luck and have fun creating coins.