As PC gamers in South Africa are aware, cryptocurrency miners around the world are buying top-end graphics cards, causing a global shortage.
While Radeon RX470, RX480, RX570, and RX580 cards are preferred for mining cryptocurrencies like Ethereum, miners who grew tired of waiting have cleaned out Nvidia cards as well.
Wootware and Raru told MyBroadband that the waiting lists for cards are extremely long – up to a month for Nvidia cards or up to 10 months for Radeon RX cards.
Beating the shortage
Waiting without guarantees that I will receive the six GPUs I wanted for a mining rig did not sound promising.
When you’re buying graphics cards in batches of six during a shortage, it’s time to use the big guns – Amazon.
Like everywhere else, Nvidia GTX 1070 cards were in short supply. You could get one here, one there, all from different suppliers and manufacturers, all at varying price points – ranging up to $650 excluding shipping and taxes.
However, Amazon had just received a consignment of Nvidia GTX 1080 cards from PNY for $499 each.
I calculated that I needed to land the cards for under R9,000 each for a good return on investment, which at R13 per dollar came to roughly $690 per card – including shipping and taxes.
After researching, I learnt it was possible to mine with a GTX 1080 rig, though it wouldn’t be as efficient as mining with a GTX 1070 rig.
By the time I decided to place my order on Amazon, I could only take three of the PNY cards, though. Fortunately, there were also three overclocked versions of PNY’s GTX 1080 available for $549 each.
I bought my six graphics cards, although I would only know exactly what they cost when the credit card transaction cleared.
After ordering the cards, I placed an order for the rest of the rig’s components from QiT – a company which operates in my neck of the woods.
They quoted me R15,123.24 for a fully-assembled rig with dual 850W power supplies and a Biostar TB250-BTC motherboard. All I had to do was install the graphics cards and connect the PCIe risers.
Incredibly, five out of the six graphics cards I ordered from Amazon arrived before QiT delivered the rig.
I ordered my cards from Amazon on a Thursday evening. On Sunday, the first three were in South Africa. On Monday, the courier handling my order called to get my ID number or importer’s code.
Customs released the items immediately, and by Wednesday they were in my hands. For those keeping count, that is less than a week to order a graphics card from the US and have it in my hands in South Africa.
The next two arrived the following Monday, and the last one on Wednesday. Overall, less than two weeks to get six PNY Nvidia GTX 1080 graphics cards.
In all, the cards came to R52,247 – R24,787 for the standard PNY units, and R27,460 for the overclocked variants.
Putting it together
With the graphics cards and rig before me, I put it all together. Installing the cards on QiT’s rig wasn’t rocket science, and neither was connecting the PCIe risers and power leads.
Testing one card worked like a charm, and everything kept working after installing two more. When I added the last three, however, things started to get complicated.
With the Biostar TB250-BTC motherboard, you have to go into BIOS settings and put it into “mining” mode for it to detect six GPUs.
When running the mining software, things worked for a while, and then the graphics driver crashed – causing the mining software to crash. Upon restarting the software, only five of the six GPUs were detected.
After hours of unplugging and plugging power and data cables into the risers, and tweaking settings in software, the rig started running without crashing. I still have no idea what fixed it, as I’m pretty sure everything is exactly the same as when it crashed.
GTX 1080 GDDR5x and Cuda mess
The hardware was not the only aspect of the rig with complications. Testing Claymore’s Ethereum miner showed the rig’s hashrate was lower than I had hoped.
It seems there is an issue with getting the full 10GHz of memory bandwidth out of the GDDR5x video RAM used in the GTX 1080.
Trying to force the power state of the graphics card into the P0 high power state through the usual methods also doesn’t work.
The GTX 1080 performed much better when switched to NiceHash, though, a multipool mining platform that calculates the most profitable algorithm to mine at any given time.
According to the NiceHash profitability calculator, my cards will have paid for themselves in 7 months. At the same profitability levels, the whole rig should be paid off in under 9 months.
However, profitability on NiceHash has decreased dramatically in recent weeks, likely due to an influx of miners on the platform.
For now, the rig is making money, with a hope that it will pay itself off one day. If that stops, we will have an awesome set of graphics cards for several gaming PCs.