We all know it: much of the crypto mining scene is being taken by ASIC's lately, which SHOULD mean that GPU mining is finally coming to an end, right? And whit Ethereum switching to POS on the near horizon, it seems even more evident.
When it comes to Ethereum scene, ASIC's are also slowly, but surely, taking over. So why would anyone build a GPU based mining rig in this day and age? Well, I built one, and I will write here my personal experience with it.
For the following calculations, I will use my country's (Mexico) electricity costs. However, I must mention that I have managed to get (legally) really cheap electricity, so my earnings would be much higher when compared to paying domestic electricity rate. Nevertheless, we assume we are paying our electricity billing normally.
Let's make raw assumptions here: take for example, Antminer E3, which gives about ~190 MH/s with a power consumption of ~760 W (according to CryptoCompare: https://www.cryptocompare.com/mining/bitmain/antminer-e3/) . Using my country electricity costs, I would end up paying about 500 mexican pesos (MXN), which is about ~27 USD monthly. Calculating profitability, we get this:
So the montly profit would be 86 - 27 = ~$59 USD monthly, which considering Antminer E3 price of about 1300 USD, gives us an aproximate 22 months return on investment. Ouch
Now, for the mining rig I built. I will try to make it not so boring, so I will cut to the chase: I built an 8 GPU RX 570 mining rig, which gives me ~223 MH/s with a power consumption of about 1280 W. I did get a deal on the GPU's (or so I think), each one costing me about 145 USD (~2750 MXN), so the total cost of the mining rig comes down to about $1800 USD. Calculating profitability, we get this:
Considering the power consumption, I end up paying about 52 USD per month, then my profit is 101 - 52 = $49 USD monthly, which considering the rig building price of 1800 USD, gives us an aproximate 36 months return on investment. Ouch again.
At the rate I got, however, It would take me ~18 months to get my investment back, lower than the ASIC on a domestic rate, but still kind of a long time. If I had the ASIC with my current rate, it would take me about 12 months to get my ROI.
So an ASIC is way better than GPU mining, at least for Ethereum, right? Well, not really; if the cryptocurrency you are mining ends up changing it's algorithm, or killing mining altogether, you will very likely end up with a really expensive paperweight, whereas with a GPU rig you will most likely find another cryptocurrency to mine (albeit less profitable most likely) or just sell your rig and get some of your investment back.
So, long story short folks, I do believe hardware mining is in a state of decadence, perhaps for the best, since it also affects our ecosystem. I also believe it's hardly profitable nowadays (unless you can get free electricity), so why did I built a GPU mining rig in the first place? Well, I do like the idea of Ethereum remaining ASIC-resistant, even if it will change to POS in the near future, and, well, I just like the idea of being a miner and somehow contribute to the network, even if I am a bit late to the party.
Thanks for reading! And sorry if the post seemed long.