This guide follows on from Part 6 of my step by step guide on how to build a 6 GPU Mining rig and explains how to connect up and flash all 6 graphics cards.
If you have been following my previous articles, you should have an open air mining rig setup with a single GPU connected and flashed. You should be hashing around 30Mh/s mining Ethereum on Nicehash. Now we need to connect the other 5 GPU’s!
Installing 6 GPU’s
It’s best to connect each GPU one at a time, flash the card, test it in Nicehash and then disconnect the card from your rig before moving onto the next card.
Trying to connect all the cards at the same time and flashing them in Windows can lead to mistakes i.e. you flash the wrong cards with the wrong rom. Also the ATI Winflash interface only shows 3 cards anyway. Finally if there is a problem with any of your cards it’s much harder to identify/resolve with 6 connected at the same time.
!!! Warning flashing your cards will void your GPU warranty. In addition running your cards 24/7 at overclocked settings may cause them to fail quicker than with normal use. Proceed at your own risk!!!
Disclaimer over – the procedure you are going to follow for each card is:-
- Power down your mining rig.
- Unplug the 8 pin power cable from GPU #1 and remove the USB riser from the bottom of GPU #1.
- Install GPU #2 into the next available slot on your frame.
- Connect up the power cable and GPU riser you just removed from GPU #1 to GPU #2. If you need a recap on how to do this check out Part 3 here.
- If the card has a manual switch for two BIOS settings, make sure it is switched to the overclock setting.
- Plug your monitor into GPU #2.
- Boot up your rig and follow the flashing procedure in Part 6 here.
- Test out your hash rate in Nicehash and monitor your GPU temps and settings in GPU-Z. Because you are using the same PCI-E slot you should not have to run the benchmarks again.
- Repeat for GPU #3, GPU #4, GPU #5 and GPU #6.
Connecting all 6 GPU’s
Once you have all cards flashed and hopefully hashing at 30Mh/s+ each, we now need to connect them all together at the same time. First you need to power down your rig.
How you connect up your cards and risers will largely be dependant on your PSU. Different PSU’s come with different cables and ports.
The one thing which I really would try to avoid using is the SATA to 6pin/4pin converters that come with your risers. They are not designed to power GPU risers, SATA power cables are designed for hard drives which use much less power. Using SATA converters, especially connected to multiple risers can cause the cables to overheat.
Ideally you would connect one GPU and one riser to a single power cable from your PSU. However, most PSU’s do not have enough split pin PCI-E cables to do this, or they are simply not long enough. If this is the case you will need to use a combination of 6 pin extension cables and 4 pin molex cables to power your risers.
I have done a full guide here explaining how to connect up all 6 cards and risers. If you have any questions please let me know in the comments section.
Booting Up Windows
Once your cabling is sorted out you can boot up Windows with all 6 GPU’s connected for the first time. Windows 10 Pro should automatically identify all 6 cards. You can check this by opening up GPU-Z and selecting each card from the drop down list.
Assuming all 6 cards are listed it’s time to fire up Nicehash. If you want you can go ahead and run a full benchmark for every card on precise settings. If you have different cards installed then you will need to do this. However, if you have 6 identical cards (even if the memory types are different) then there are a few of downsides to bench marking all of your cards:-
- It will take considerable time (probably 2 hours plus).
- If you are using identical cards the results should be fairly similar, even with different memory.
- It’s possible that small differences between the cards can cause Nicehash to run different algorithms for different cards. If all of your cards are identical you don’t really want this to happen as in my experience the more miners running, the higher chance of a crash.
Therefore I tend to use the benchmark we already have for GPU #1 in Part 6 and copy these settings across all remaining cards.
Copying Benchmark Files
To copy the benchmark results for your first card you need to open Nicehash will all 6 GPU’s connected. Click on benchmark and then click “save and exit”.
This will create a blank benchmark profile for the 5 remaining GPU’s. You can now open the config folder in your Nicehash folder and you should see something like this:-
If you open the first benchmark file in notepad you will see the first three lines look like this:-
“DeviceName”: “Radeon RX 580 Series”,
You need to copy and paste all of the code from the second line down to the end of the code i.e. from “DeviceName”: “Radeon RX 580 Series”, onward. You then need to open up each of the other five benchmark files, delete everything under the first two lines and paste the code you copied from the first file.
Save and exit all five benchmarks and then you are good to go with Nicehash.
Hopefully if all has gone well you now have a miner that will hash 180Mh/s + on Ethereum. My rig has three Hynix memory RX 580’s and 3 Samsung RX 580’s. The total rig averages around 181Mh/s. You can see below the three Hynix memory cards are pushing around 29.5Mh/s and the three Samsung cards at 30.5Mh/s.
At the time of writing (November 23 2017), this was giving me around $10.50 of bitcoin a day, or $315 a month.
Switching to cryptonight you can see my average hash rate is just under 5kh/s. The three Samsung cards are again all slightly higher ( 840h/s range) than the three hynix cards (810h/s range). Overall at the time of writing this was giving me about $12.00 a day or $360 a month.
Remember the above rates are obtained without spending countless hours adjusting clock settings to try and get the optimum hash rates. Can you get higher rates with these cards? Sure, but we are talking less than 5% increase in most cases, if at all.
We have literally spend no time at all flashing our cards with pre-made roms that requires no knowledge messing around with clock speeds and voltages.
And here is the end product:-
That’s it for part 7 of my 6 RX 580 GPU mining rig guide. In part 8 we will look at setting up auto restart in case of a power cut or crash.