In 2017 we bought a GPU mining rig and mined enough Ethereum to cover our costs.
Then our mining power hit the wall as the blockchain’s difficulty increased and we stopped making the big bucks.
Four of the Aorus RX 580 4GB graphics cards from the rig were quickly claimed by co-owners of the machine, leaving the rest to sit in a cupboard.
Until now, that is.
It was time to turn our mining rig into a gaming PC.
The idea behind the conversion was to save as much money as possible by using parts from the rig in the new gaming PC.
This quickly proved to be a challenge, due to the components on hand.
Graphics cards were not a problem, as the RX 580 4GB is still a capable card and you can run two in CrossFire to get more power out. The only limit may be in high-resolution gaming where the 4GB of VRAM will prove a bottleneck.
Many of the other components, however, left much to be desired.
After taking apart the rig, shown above, the first item for stock take was the RAM.
We had a very plain looking stick which measured 4GB in capacity. Not enough for high-end gaming and definitely not pretty enough to put in a gaming PC case with a clear side panel.
The next item on the menu was the CPU.
An Intel Celeron G3900, which packed an underwhelming 2 cores and 2 threads, with a base frequency of 2.80GHz.
The 14nm processor was also not suited for high-end gaming.
Adding to the list of potential problems was the case – or rather the lack of one.
Our mining rig was built on an open frame to keep it cool and accommodate the six GPUs it was running.
A new case would need to be purchased to protect the gaming PC and in case we wanted to transport it.
The motherboard which came with the rig was made for mining, and while it featured support for Intel LGA 1151 chips, it only had one full-size PCIe slot.
Five PCIe x1 slots are also on the board – which came with seperate powered PCIe risers so the graphics cards could be connected. Two RAM slots which can handle DDR4-2400 memory were also present.
While not a train smash, it was not an ideal platform to build our gaming PC on.
Another issue was that our rig came with a 60GB SSD – enough space to run Windows 10, but not much more. More storage would have to be purchased.
A standout piece from the rig, however, was the Andyson 1,200W PSU. It was fully modular and Platinum power rated.
The PSU would have enough to power almost any gaming PC and it would save us a few grand in the build price.
As stated in the beginning, graphics cards were taken care of.
We had two GPUs left, although one of them had a damaged fan on its cooler. It did not spin straight and made quite a noise.
Fortunately, the remaining card was working fine.
The new pieces
Following an assessment of the mining rig, the following shopping list was made.
- 500GB SSD or 1TB HDD
The case we chose was an NZXT H440 mid tower with support for an ATX motherboard and a 4-fan system built in. (It was on special for just over R1,000.)
The motherboard, CPU, and RAM was taken care of thanks to an upgrade kit from a local PC retailer, which was also on special.
The kit included an AMD Ryzen 5 1600X processor, MSI X370 Gaming motherboard, and 8GB of DDR4 2,666MHz RAM. The kit also included an AMD Wraith Max cooler for the CPU. This set us back R5,999.
For the storage, the need for speed outweighed space and a Kingston 480GB SSD – R1,200 – was selected.
Building the PC
Unfortunately, the build did not go as smoothly as the shopping.
Under the watchful eye of our resident PC gaming expert, we installed the CPU and its included cooler, the SSDs, the RAM, and one of the RX 580 cards.
We then inserted the power supply after attaching all the cables and began routing them to the motherboard. All was hooked up, barring one cable – the molex connector for the case fans.
The NZXT case comes with four fans built in – three 120mm in the front and one 140mm in the rear. These are connected to a PWM fan hub which has all the fans connected to it.
You then connect the fan hub to the motherboard with a single PWM connection, and power the fans with a molex cable connected to the PSU.
And this is where the problem arose. The mining rig and its power supply did not come with the required molex cable when we bought it – as the rig was pre-built and had no fans.
Several visits to PC gaming forums and phone calls to locale PC hardware retailers presented us with sad news.
- Modular power supplies often have unique pin layouts, meaning an Andyson cable may not work on other PSU brands and vice versa.
- You cannot buy a single PSU molex cable, and our best bet was to buy a modular PSU full cable kit that worked with our PSU. These costs around R1,000.
- Splicing an existing PSU cable – for example, for SATA power – and putting a molex connector on it could result in some fireworks in our case.
- A PC builder who could make us a custom cable was going on holiday and would only be able to assist in 2019.
After running our PC with no case fans to see if the remaining components worked, we negotiated with a colleague to buy the Andyson PSU and we would use the funds to buy a new Corsair power supply.
The finished product
With the new Corsair PSU installed and everything plugged in, the gaming PC was operational.
In the end, only a single RX 580 and the 60GB SSD survived from the rig.
It turns out Compulsive Upgrade Disorder is a real ailment, while single PSU molex cables do not grow on trees.