PLEASE NOTE: the guide below was written back when Litecoin mining on GPU’s was profitable. I recommend the AntMiner L3+ Litecoin Miner (ROI in about 100 days, currently) or building an Ethereum mining rig by following my 6 GPU Mining Rig Guide as it is updated weekly and utilizes current 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
- Un-package it all
- Build / assemble custom open air mining case
- Install processor and RAM on motherboard
- Plug in all riser cables
- Place motherboard in custom open air mining rig case and connect motherboard PSU connector (leaving PSU unplugged from the wall of course)
- Plug in SATA hard drive (or optional Linux on USB stick)
- 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.
- Plug in all power supply connections
- Connect mouse, monitor and keyboard and an internet connection (I use a USB WiFi adapter)
- Check all connections once more
- 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!
Sidenote: If mining isn’t your thing, and you are just interested in purchasing some cryptocurrency as part of your investment portfolio, I personally use and recommend FTX Global Crypto Exchange (Use FTX US if a US resident)
After you have all the hardware in hand that you mentioned above, how much time from start to finish would you say install would take? Without glitches…….With glitches?
Without glitches: 2hrs. With glitches: 4hrs? It depends somewhat on your comfort level and experience assembling modular computer parts like this.
Here’s a dumb question, but how should I load Win8 onto this system since it comes on a DVD? Should I hook up the hard drive to my regular desktop PC and try to load it that way, or should I pull the DVD drive out of my desktop and temporarily hook it up to the minerbox to load the OS?
You can use a USB DVD drive or temporarily connect a standard desktop internal optical drive. Alternatively, you can install Windows from a USB stick, but that involves some configuration of files, etc.
Dude, I am building your 6 gpu rig now. Will let you know how it turns out.
When doing a six card rig, is it essential that all cards are the same or can you stick any combination in there?
You’ll have less configuration headaches if you make them all the same.
@admin could you please update the article to show which PCI-e slots you use (they are labelled on the motherboard – 1 is nearest the CPU, and 7 is at the edge of the board). Also for the 16x slots, are you using 1x to 16x risers in the slots (with the 1x side in the slot on the board and the 16x attached to the GPU).
You cannot mine wiht 6 GPU on Windows 7.
Only 4 GPUs accessable and fifth and sixth are going to be installed but reported as disabled with error in Win 7.
Only Linux is ok with 6 GPUs but they are unstable for me so far on ubuntu 12.04
Correct. Windows 7 has a hard time addressing more than 4 GPU’s without some complicated ‘hacking’. I’ve updated the article with Windows 8 which supports this 6 GPU build.
I have bought all the hardware specified in this tutorial except I have chosen MSI HD7950 Twin Frozr II cards. I think this makes no difference, but here is the rub. I have installed Xubuntu 12.04 on a USB key. I can get the system working with 3 cards, but not more. I get a variety of weird oddities. I have tried with two separate motherboards+CPU+RAM combinations.
Here’s what happens when I connect the graphics cards to the following slots:
The following work
2 * 1x PCI + 1 * 16x PCI
3 * 1x PCI
The following combinations do not work:
2 * 16x PCI nothing works, PC gives a black screen
4 * 1x PCI then one of the 4 cards does not work – aticonfig says it cant find the temperature of one card – looking in Catalyst settings, there are 4 monitors, but one card is not recognised. Changing the order of the cards makes no difference. I rescan and reboot each time.
1 * 16x PCI + 3 1x PCI nothing works, PC gives black screen
Given the tutorial is for 6 GPU cards running together, I figure I must be missing a small detail.
footnote: the motherboard third 16x slot says “you must use an 3rd Generation Intel Core processor to enable 3rd PCI Express slot”. I have not removed the sticker from this slot and I suppose the Celeron processor specified is not 3rd gen?
I had a look at the spec-sheet for the Celeron G1610 processor http://www.intel.co.uk/content/www/uk/en/processor-comparison/processor-specifications.html?proc=71072#graphicsspecifications and if you look under where it says “PCI Express Configurations up to 1×16, 2×8, 1×8 & 2×4” – not sure if that is relevant.
I double checked the CPUs I bought, they are the exact Model: BX80637G1610 as specified on the Amazon link which matches the code on the CPU box.
Any ideas would be really appreciated 🙂
Have you figured out how to run more than 3 cards? I’m having the same problem with only 3 that work.
I had this random problem with one of the rigs I built. You can use dummy plugs, or as I did, just plug a monitor into the GPU that isn’t running to ‘activate’ it.
I left some of this same info on the 4 card 7970 comment, but wanted to leave some of that info here as well. I built this rig as well, but only used 5 7950’s and I’m glad I did.
I run cgminer on Linux and I’ve never been able to undervolt. With 5 cards, they are using 1770 watts once they heat up! Of course with scrypt mining there is a little more fluctuation that bitcoin mining, but I’m still averaging well over 1700w. Think I’m going to add a 2nd power supply using the Add2psu because I just don’t feel comfortable running a 1600w power supply like that long term.
I’m running 5 of these with 2 of them using powered risers. The reference style fans are loud (!), but they really do work better partially because they expel hot air in the back. In a cool room you might be able to get by without using a box fan with these, or at least running the box fan on low.
And lastly, I bought 6 of the Sterilite crates and they work, but the ones by United Solutions like this are superior. I bought mine at Lowe’s Hardware for $6, but they don’t sell them online. The United Solutions crates are about an inch wider and made of a more rigid plastic. Because it is more rigid, there is less plastic on each of the beams in the grid meaning the holes are larger and airflow is noticeably better not to mention more room for the cards. The Sterilite crates are so soft that you can actually cut them with a good pair of scissors!
Yes, unfortunately Linux doesn’t allow undervolting, so Windows is the best choice for undervolting multi-GPU rigs. This in my mind is important as it reduces your power usage and improves profitability.
What temp are your cards running at? I’m using 3×7950 using your exact configuration. They are running at 72, 92, and 90 C respectively, which seems really hot to me. Just one card runs at 72. What is considered a safe range for temperature?
What OS do you use to run all the 6 GPU’s ?
When I mine the computer becomes so slow, the mouse movements are very slow and jerky. Obviously I don’t intend using the machine for other tasks, but even to get a terminal window up so I can monitor cgminer takes a lot of effort. Is it a CPU bottlekneck? What could be done to improve it? I’m using your exact configuration above.
The Gigabyte HD7950s have 1 x 6-pin and 1 x 8-pin connectors to get power directly from the PSU, do i still need powered riser cables for pci-e x1 or x16?
Most of the card’s power comes straight from the power supply through power connectors. However, some of the power comes through the PCI-E connection to the motherboard. Using a powered riser ensures this additional PCI-E fed power also comes from the motherboard. In multi-gpu rigs this is a good idea as it reduces the power strain on the motherboard.
Hi
I have a question about the risers
You suggest to buy 6 riser 1x 16 but the mobo supports 3 (1x 16) and 3 (16x 16)
How come?
I’m wondering if its bad to have possibly all 6 GPUs powered by the power riser cables?
Is that possible?
Or is it 100% safe to only have one?
Thanks!
I would recommend using all powered riser cables on a 6 GPU rig (especially if you’re using the 1x to 16x cables). If you are using 16x to 16x, you can get away with 3 of each.
How many7990 could I use with with the set up u posted ?
Good question. I’ve never used the 7990, so I can’t speak from experience. I read on the bitcointalk forums that it isn’t the best card for mining.