As a follow-up to my incredibly popular 6 GPU Mining Rig Guide, I’ve decided to write a guide on how to build an 8 GPU Mining Rig.  Generally speaking, the more GPU’s you can fit on a mining rig, the better. Historically, the motherboard, power supply unit and operating system have been the limiting factors to how many GPU’s a mining rig can support. When I first started building crypto mining rigs in 2013, 4-5 GPU’s were the most you could feasibly install. That number has slowly increased to where 6-8 GPU rigs are now easily achievable even on large scale crypto currency mining deployments.

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 Voyager. Download the app and trade $100 to get $25 of free Bitcoin. Use code JOSWDN to claim your free BTC.

With that little history lesson behind us, let’s get started on the guide.

8 GPU Mining Rig Hardware Build List

Just like in the previously mentioned guide, the idea is to build a custom open-frame mining computer to maximize airflow and cooling. An 8 GPU mining rig will throw off a fair amount of heat, so an enclosed PC case is simply not a good option. We also will need riser cables to allow enough space between the graphics cards and lift them away from the motherboard that supports them.

2x Power Supply –  2x EVGA 750 watt power supply and dual PSU link cable – For this rig, we are going to use two 750 watt PSU’s connected to the motherboard via the dual link cable. This allows both power supply units to start and stop at the same time when the switch from the motherboard is turned on or off. Using a gold or platinum rated PSU means higher efficiency in terms of power usage.

1x CPU –  Intel G3900 Skylake Celeron CPU  – this low powered CPU is perfect for building a mining rig. Since all the work is done by the GPU’s, the CPU should be as cheap and as low powered as you can find.

8 GPU Compatible Motherboard  – What is the best motherboard for an 8 GPU mining rig? I’ve listed below my favorite motherboards that are compatible with 8 video cards. Keep in mind, we will be using an M.2-to-PCI-e adapter to add the additional GPU’s. Pick one Motherboard from the list below to build your rig. They are listed in the order I would recommend them depending on availability.

• ASUS PRIME Z270-P LGA1151
• ASUS PRIME Z270-A LGA1151
• ASUS PRIME H270-PLUS
• ASUS ROG STRIX Z270E GAMING
• MSI Enthusiastic Gaming Intel Z270

8x Graphics Cards (GPUs) – Nvidia GTX 1070 –   After benchmarking several models, my favorite version of this GPU for mining is the Gigabyte GeForce GTX 1070 Windforce OC (model # GV-N1070WF2OC-8GD). It has a twin fan design and seems to run cooler than most of the other 1070 models I’ve tested. If that model isn’t available, any 1070 with a twin fan cooling design will work well.  If this GPU is completely sold out, I recommend checking eBay  or looking at some of the other GPU recommendations in my mining GPU comparison guide.

A close second choice for a GPU would be the AMD Rx 580 8GB which you can currently find on eBay and Amazon at very reasonable prices. Sometimes Amazon limits the number of GPU’s to 3 per customer, so I would recommend grabbing 2 GPU’s from the link above as well as this AMD Rx 580 8GB 6-Pack. This particular pack of special edition Rx 580’s are overclocked already and ready to mine at maximum hash rates out of the box.  All mining rig build requirements are the same for either the 1070 or the Rx 580. The primary reason I like the GTX 1070 is the lower power usage (100w vs 135w per GPU) when mining.

1x RAM (System Memory) –  4 GB DDR4 RAM – This is the least amount of RAM I would recommend for a Windows or Linux based mining rig. Mining doesn’t take much system memory since the memory on the GPU’s are doing all the heavy lifting.

8x USB Riser Cables –  USB Riser Cables – I’ve linked to a 6-pack of riser cables, so you’ll want to buy an additional 2 cables for a total of 8 riser cables. These are the best riser cables I’ve found in terms of quality (I’ve purchased a lot of cables from this seller with no cable failures so far).  These USB riser cables separate the 8 graphics cards from the motherboard and allow spacing between cards for heat dissipation.

2x M.2 to PCI-e adapters – This M.2 to PCI-e adapter allows you to add the 7th and 8th GPU on the motherboard since the motherboard doesn’t have 8 PCI-e slots out of the box.

1x Hard Drive (SSD)  –  Solid State Drive  for installing operating system and your mining software. I recommend at least a 60GB SSD to allow for a large 20-24GB page file. Mining software requires a large page file on the hard drive.

1x Custom Mining Case –  I’d recommend an Open Air Mining Case.  This Vedhha case is better than a lot of the options currently available on the market.

Operating System – I recommend mining on Windows 10.  It has the best driver support for an 8 GPU mining rig.

Monitor, Mouse and Keyboard to configure all the software settings, initially.

Assembling the Custom Ethereum Mining Hardware

1. Un-package everything
2. Build / assemble the Open Air Mining Case.
3. Install processor and RAM on motherboard
4. Plug in all riser cables and M.2 slot adapter.
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. 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 Windows 10 (more details below for configuring mining software, etc).
12. Make sure fans are fully functional. Start the mining software, tweak settings for maximum hash rates and let it run!
    

8 GPU Mining Rig Hardware and Software Configuration

1. Update the motherboard to the latest BIOS using a USB thumb drive. You can find the latest BIOS.
2. Configure Motherboard BIOS with the following settings changes:
   • Set PCI-e settings: PEG 0 and PEG 1 set to Gen1
   • Above 4G Decoding (cryptocurrency mining) should be set to Enabled
   • OS settings: disable Windows 7, enable Windows 10 UEFI
   • Save and reboot
3. OS / DRIVERS / MINING Setup:
   1. Boot from Windows 10 USB install media (you can buy it pre-loaded or build your own on the Microsoft website).
   2. Install Windows 10 Pro x64
   3. Install Nvidia Drivers
   4. Install MSI Afterburner and set memory clock to 600, and power to 70. This will give you 30Mh/s per 1070 GPU
   5. Install any system drivers that didn’t auto-install (check device manager)
   6. Rename PC to mining worker name. Something like Minion001, Minion002, etc.
   7. Install Claymore Dual Miner, edit the config file with your Ethereum address and miner name. Drop a shortcut to the mining software .exe file in your system startup folder if you’d like to auto-start mining when Windows boots up. You can find the system startup folder in Windows 10 by going to: Start > Run  and entering ‘shell:startup’.
   8. Disable windows update using this guide.
   9. Set power profile to ‘always on’
   10. Install your favorite remote access software, especially if you plan to have more than one rig to manage.
   11. Fire up the mining rig and rake in those crypto coins!

Something I’ve done when building out a whole mining farm, is to do the OS/DRIVERS/MINING setup and then just clone the solid state drive using a 2 bay hard drive dock with offline clone feature built in.

Congratulations! Your 8 GPU Mining Rig is ready to start mining for crypto!  Be sure to also check out our reviews of the best Litecoin mining hardware and Bitcoin mining hardware.

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)