After building our first mining rig we got cost conscious very fast. We didn’t have hardware laying around that we used to build our mining rigs. We bought all our parts new, and as we all know building an efficient mining rig isn’t cheap. When we got started, the payoff period for a 6 GPU rig was about 9 or 10 months. So, like most that have turned down one of the crypto mining roads we started looking for ways to maximize hardware purchases.
Our goal: An 8 GPU mining rig
At the time, getting to 8 GPUs per mining rig, or more correctly, per motherboard was talked about like a unicorn. In fact, running Windows 10 as an OS, which we did, made getting past 6 GPUs a chore. But, there were miners running rigs with 7 and 8 GPUs, and how many of them got there was with an M2 to PCIe adapter. Once we had a good combination of hardware that allowed us to stand up a 6 GPU rig without much trouble, we set our sights on 8 GPUs.
M2 to PCI-e Adapter: the missing link
For our setup, what we learned was that while Windows 10 would recognize up to 8 GPUs (at least that was what we had been told) getting our motherboard to required a lot of fiddling around. Well, that was until we learned about the M2 to PCI-e adapter method.
As you read below, the motherboard we were using actually has 8 PCI-e slots. Just because they were there didn’t mean they were going to all cooperate, however. In our situation, we turned to a clever card that transformed an M2 SSD slot on the motherboard into another PCI-e slot.
Our hardware selection for our 6 GPU mining rigs
With a lot of research and luckily not too much painful trial-and-error, we arrived at a repeatable collection of hardware that made getting to 6 GPUs easy. Even with Windows 10. Here’s what we used (and still use on many builds today, Ethereum and otherwise).
Starting your first build? Does a 6 GPU Miner sound good?
Check out our step-by-step guide: How to build a 6 GPU Mining Rig!
6 GPU Ethereum mining rig parts list
- (1x) ASUS Prime Z270-A Motherboard (also try Z270-A Motherboard)
- (1x) Intel LGA 1151 Processor
- (1x) 4GB DDR4 Desktop RAM
- (1x) Corsair 1200W Platinum PSU *
- (1x) Powered Mining GPU Riser Cards 6 Pack
- (1x) 60GB+ SSD
- (6x) GTX 1070 GPUs – we prefer EVGA SC or EVGA SC Black
- (1x) USB WiFi Adapter or Ethernet Cable
- (1x) 6 GPU Mining Rig Frame (or just buy a cheap Home Depot wire rack like the one we use)
- (1x) USB Flash Drive (any USB Flash Drive that is 5 GB or larger)
- (1x) 20+ Nylon Cable Ties (also called Zip Ties)
- (3x) PCI-e Y-Splitter – ** may need if not using the Corsair power supply above
* EVGA’s SuperNOVA 1200 P2 80+ platinum is another PSU we also run that will work great with this build.
Beyond that, all you need is a little bit of software to get it all running. For us, that has historically been an OS (Windows 10 on a USB Stick), MSI Afterburner and your mining software of choice. Our go-to was Claymore’s Nvidia Dual Miner at that time.
So, this is a good setup. You can come up with something a bit cheaper with a different motherboard, but this one was the most straightforward to get 6 GPUs running out of the box. And, it was also the one that we had seen most frequently running 7 and even 8 GPUs.
Building an 8 GPU mining rig
Starting with our 6 GPU setup getting the 7th GPU wasn’t difficult. We used one of the remaining open PCI-e slots and picked up another small PSU to handle the load. You can take a few routes depending on your mining operation ambitions. At this time we were buying lower wattage Platinum PSUs that matched the manufacturer of the 1200 watt unit that was powering most of the setup.
Now we’re getting somewhere. We’re running 7 GPUs and all of them were posting up with limited tweaks to the BIOS and nothing more than the standard Windows 10 settings we had become accustomed to using. Getting to 8 GPUs, however, wasn’t working even though we had one more open PCI-e slot.
Our savior: an M2 to PCI-e adapter
We eventually gave up on the 8th slot on our Z270-a. Whatever we tried, including far too much time tinkering with motherboard settings and drivers, the 8th card simply wouldn’t post in that remaining PCI-e slot. When we were researching other 7 and 8 GPU rigs we came across the method of creating an additional PCI-e slot out of the motherboard’s M2 SSD card slot and decided to give it a try.
Here’s the adapter we used. The name is – get ready for a mouthful – MintCell M.2 M (M2) Key NGFF to PCI-E (PCIE) 4x Adapter With 4 Pin MOLEX Power Cable v1.0. It’s killer 2.5 star rating combined with it’s sub-$8 price had us buy two just in case.
As it turned out the first one worked out of the box. When we booted up, the BIOS posted the card as what it actually was, our 8th GTX 1070, and Windows correctly recognized it as well. From there, we asked Claymore to do some work and it also obliged.
Updating our 6 GPU shopping list to 8 GPUs
8 GPU Ethereum mining rig parts list
This is the list of hardware you need to build an 8 GPU mining rig.
- (1x) ASUS Prime Z270-A Motherboard (also try Z270-A Motherboard)
- (1x) Intel LGA 1151 Processor
- (1x) 4GB DDR4 Desktop RAM
- (2x) Corsair 1200W Platinum PSU *
- (2x) Powered Mining GPU Riser Cards 6 Pack
- (1x) 60GB+ SSD
- (8x) GTX 1070 GPUs – we prefer EVGA SC or EVGA SC Black
- (1x) USB WiFi Adapter or Ethernet Cable
- (1x) 8 GPU Mining Rig Frame (or our favorite… the Home Depot wire rack)
- (3x) PCI-e Y-Splitter – ** may need if not using the Corsair power supply above
With the updates we’ve added you’ll end up with an 8 GPU mining rig with 4 extra powered PCI-e riser cards and some extra power from the second 1200W PSU. The second 1200W PSU can be switched out for a low wattage platinum PSU if you’re not building additional rigs. if you are, you can share the remaining power the 1200W we suggest uses. The Dual PSU 24-pin cable is used to wake the second PSU up as it never gets a load signal from the motherboard when just powering GPUs.
Please note that not all Z270’s are created equal. The ASUS Z270-A is the specific motherboard we’re speaking of. We have seen others that have less PCI-e slots (or interest in getting to even 7, never mind 8 GPUs).
* EVGA’s SuperNOVA 1200 P2 80+ platinum is another PSU we also run that will work great with this build.
Look up pcie splitterd