Guide to Building a 6 GPU Mining Rig

PLEASE NOTE: the guide below was written back when Litecoin mining was profitable. I recommend my 6 GPU Ethereum Mining Rig Guide as it is more recently updated (2017) and utilizes newer graphics card and build options. Happy Mining!

Building a mining rig with more than 4 graphics cards has its challenges. There are operating system limitations, power requirements and hardware issues to sort out. However, following the success of our Budget Litecoin Mining Rig Build Guide and mid-range 4 GPU Litecoin Mining Rig Build Guide, we’ve decided to do the research and publish a guide showing you how to build a fully functional 6 GPU mining rig. Once assembled and configured correctly, this mining hardware is capable of roughly ~2,700 Kh/s of scrypt mining power. As of the date this guide was updated, a 6 GPU Litecoin mining rig like this, can generate over $250 USD worth of Litecoins per month. It will cost you roughly $1,800 to build. If you want to see the live current calculation yourself, click here for a Litecoin calculator. You’ll just have to enter your electricity rate to calculate your net profits. You can also use this rig to mine any other Scrypt based digital currencies like Dogecoin, Reddcoin, etc. Build time should be right around 2 hours. You can find an excellent photo set here of how this rig looks like all built.

6 GPU Litecoin Mining Hardware Build List

• Power Supply – $250 –  1300 watt Gold Rated PSU  –  If you are having a hard time finding these larger power supplies in stock, an alternative is to get  two lower powered 750 watt Gold Rated PSU’s and connect them together with this add2psu adapter to power your rig. 
  
• Motherboard/CPU – $160 – H81 Pro BTC motherboard coupled with the Intel G3220 CPU. If you can find one reasonably priced, the MSI Z77A GD-65 is also an excellent motherboard combined with the inexpensive Intel Celeron G1620 Ivy Bridge Processor .
• Graphics Cards (GPU) – 6x $200 – AMD Radeon R9 270. This GPU is capable of 450Kh/s. Running six of them will net you a total of 2,700Kh/s.  I recommend the Gigabyte, Sapphire and MSI versions of this card. If the R9 270 is out of stock or overpriced, the R9 270x costs just a bit more for slightly more hashing power (480 Kh/s) and will work with everything else in this guide.  I’ve also recommended several other GPU’s for crypto mining here. Just remember to calculate the power requirements for whichever cards you decide to go with and purchase an appropriately sized PSU or multiple PSU’s to run your rig. For example: you could build this rig with six R9 280x GPUs running at 750Kh/s and 280 watts each. You’d need to combine a 1kw PSU and a 750 watt PSU with this adapter to provide power. Everything else would stay the same, and you’d have a 4,500Kh/s rig for around $3,000 USD at today’s prices. All the other components would stay the same.

• RAM  – $40  –  4GB Kingston DDR3 RAM –  Since this will be a dedicated Litecoin Mining Rig, 4GB will be enough RAM. If you plan to use Reaper mining software for Litecoin mining or other scrypt based currency mining, you’ll want to put 8GB in this system.
• 1x to 16x Powered Riser Cables – $60 –  (6x $10) PCI Express 1X to 16X Slot Flexible Extension Cable – 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 riser 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.
• Hard Drive –  $40  –  Solid State Drive for installing Windows 8 and your mining software (alternatively you could boot BAMT from a USB flash drive)
• Custom Mining Case – $30-$80 – You can build one of these yourself with angled aluminum from your local hardware store, or ask around on the Bitcoin forum. There are several custom case builders selling them through the forum. I can personally recommend the custom built cases designed and built by Rich Chomiczewski. They are well built and reasonably priced.
• Extra Cooling  –  $30  –   Box Fan (I find supplemental cooling from a box fan to be helpful in keeping the temperatures down on the graphics cards)
• Operating System  –  $0-$90  –  Windows 8 supports 6 GPU’s, but if you’re familiar with Linux you can of course download it for free (some folks consider Linux to be the best OS for Litecoin mining, since it keeps your overall costs down, improving your litecoin mining ROI or return-on-investment). Keep in mind that undervolting/overclocking works better in Windows vs Linux for Litecoin mining due to better drivers in the Windows world. You can load almost any operating system with a thumb drive these days, but some folks might prefer to load the OS from an install CD, in which case you’ll probably want to pick up a $30 external USB powered DVD drive. Many laptops in the ‘thin & light’ category are shipping with no internal optical drive, so it will probably come in handy for other uses as well. I have one that I use fairly frequently around the house.
• Monitor, Mouse and Keyboard (to install the OS and configure the mining software, no need to buy more than one set since you only use this for setup)

TOTAL HARDWARE COST TO BUILD A 6 GPU MINING RIG: ~$1,800 for a ~2,700 Kh/s Custom Litecoin Mining Rig.

Assembling the Custom Litecoin Mining Hardware

1. Un-package it all
2. Build / assemble custom open air mining case
3. Install processor and RAM on motherboard
4. Plug in all riser cables
5. Place motherboard in custom open air mining rig case and connect motherboard PSU connector (leaving PSU unplugged from the wall of course)
6. Plug in SATA hard drive (or optional Linux on USB stick)
7. Connect all GPUs to riser cables and fasten them to custom case. Drilling evenly spaced holes in the soft aluminum slightly smaller than the screws works best. You might need to experiment for optimal spacing to keep the cards cool.
8. Plug in all power supply connections
9. Connect mouse, monitor and keyboard and an internet connection (I use a USB WiFi adapter)
10. Check all connections once more
11. Fire it up! Install the OS if needed. Install Graphics card drivers. Install mining software. Make sure fans are fully functional. Start the mining software, tweak settings for maximum hash rates and let it run!