Get the Graphics card

Remember, try not to mix GPUs brands, model and types. If you go for AMD RX series, get all of your GPUs of mining rig from AMD Radeon RX series, preferably same models and brand, for instant get 6 or 7 units of Radeon RX 570 Sapphire Nitro+ 4GB. The advantages are: 1. Easier installation and integrity in building of GPU chassis, 2. Usually mining software and mining OS doesn’t like to have different type of GPUs, may not work at all or very difficult to set up, 3. Performance and temperature monitoring is much easier, you apply in universal clock and temperature settings across are your rigs. At the beginning of June 2017, while crypto mining was booming, most of AMD RX GPUs were out of stock, started with Radeon 570, then 580 and even 560 4GB version is extremely hard to find. People started to dig again into the Nvidia world and have figured they mine very efficiently despite of initial lower hash performance per dollar of the cards. By end of June 2017, GTX 1060 3GB and 6GB versions are out of stock in most of the markets, and GTX 1050ti had a 20% price jump too from ~$140 to above ~$160. So here once again I bring back the performance per watt chart of Chapter 2 with addition of Nvidia cards. GPU TFLOPS Average Hash Power on Ethereum (MH/s) TDP (watt)

Hashpower per Watt

(higher is better) Lowest Price

Price/Performance (lower is better) GTX 1080 8GB 9 25 180 13.9 $ 550.00 22.00 GTX 1060 6GB 4 17 120 14.2 $ 280.00 16.47 GTX 1050ti 2.1 11 75 14.7 $ 140.00 12.73 RX 580 8GB 6.17 23 185 12.4 $ 260.00 11.30 RX 570 4GB 5.1 22 150 14.7 $ 210.00 9.55 RX 560 4GB 2.6 12 75 16.0 $ 125.00 10.42 RX 550 4GB 1.2 6 65 9.2 $ 80.00 13.33 RX 480 4GB 5.8 22 150 14.7 $ 230.00 10.45 RX 470 4GB 4.9 20 120 16.7 $ 190.00 9.50 RX 460 4GB 2.2 10 75 13.3 $ 100.00 10.00 R9 380 3.5 17 190 8.9 $ 183.00 10.76 R9 380X 4 18 190 9.5 $ 217.00 12.06 R9 390 5.1 22 275 8.0 $ 319.00 14.50 R9 390X 5.9 26 275 9.5 $ 355.00 13.65 R9 Nano 8.1 23 175 13.1 $ 523.00 22.74 R9 Fury 7.1 30 275 10.9 $ 355.00 11.83 R9 Fury X 8.6 32 275 11.6 $ 479.00 14.97

GPU Showdown

Note 1: Average Hash Power is based on the stock core and memory frequencies and voltages. Note 2: Lowest price refers to a time before GPUs become out of stock on July 2017

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6.5.1. AMD GPUs

The best GPU at the moment for a GPU mining rig is AMD Radeon RX 470 4GB. The other option is Radeon RX 570 4GB. However, RX 570 is not optimal, because it has a 5%–10% higher GPU core clock, and a memory clock of 1750 MHz instead of 1650 MHz, which the RX 470 has, but the higher GPU core clock means that it uses more power— the TDP of the card is 150 W, whereas the RX 470 requires 125 W. In real time and under load, the hashing power is around 22-24 MH/s, which is very similar to performance of the RX 470 with stock clocks and around 27 MH/s with overclocked speeds. According to www.1stminingrig.com, AMD Radeon RX 570 consumes 115 W of electrical power with a hashing power of 22 MH/s and 135 W with a hashing power of 27 MH/s when it is overclocked [1]. However, a new Radeon RX 470 4GB is pretty hard to buy while the RX 570 4GB is being sold at the same or lower prices. The Radeon RX 580 is totally out of the mining league because it has very bad power efficiency when compared to the RX 470 and RX 570, even though it can be purchased for a similar price. In June 2017, Radeon Rx 570 4GB was priced at around $200–$250, depending on the brand, shop and availability. Remember:

1. The memory clock frequency rather than GPU core clock frequency is very important for GPU mining performance. All RX 570 cards have memory clocks with a stock memory clock frequency of around 1750 MHz on single channel and 7000 MHz on total quad channel. Few on them have a higher frequency than 7000 MHz.

2. Forget about boost clocks! In a GPU mining rig, your GPU works at stock or lower frequencies most of the time. It does not work on boost clock all of the time. In particular, when the GPU core temperature is above 70 °C you would never see a near close to boost clock when your card works at a normal stock voltage. If you increase the power limit of the card by more than 20% in AMD Crimson software or other GPU manipulation software, you may reach the boost clock but overpowering the card will: 1. increase the power consumption and decrease the power efficiency1 _{of the card, and 2. decrease the stability of the mining rig, with}

the result that the system will tend to crash and freeze more frequently. So, what should one choose? I stick with those GPUs that have good cooling solutions, and good local support and warranty. And, of course, it all finally comes down to price. GPUs that come with a backplate operate at a lower

1 _{Read more about power efficiency and performance per watt in previous chapters. In short, efficiency is calculated by} dividing the hashing power of a GPU by the power consumption of the graphics card.

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temperature and are more robust and durable than those that don’t have one. So, when buying GPUs, these are some of the points that you should take into consideration:

1. Always check the local discounts and bargains. Sometimes, online stores such as newegg.com or Amazon offer discounts or rebates which can provide you with some saving on your total build budget.

2. Do not mix different models or brands of the GPUs if at all possible because most of the time, it is very hard to optimize the mining software settings for different GPUs. So, if you decide to use Radeon RX 570, avoid having RX 470s and RX 480s in the same mining rig.

My recommendation is Gigabyte AORUS Radeon™ RX570 4G and Radeon™ RX 570 Gaming 4G, or SAPPHIRE NITRO+ Radeon™ RX 570 4 GB. The stock core clock of RX 570 is around 1200 MHz and the memory clock is 1750 MHz.

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So, based on your budget, order four to six units of AMD Radeon 570 4GB. After RX 570 and RX 580 became out of stock in most of markets at the end of June 2017, people turn to RX 560 4GB card for mining. Radeon RX 560 4GB can mine up to 12 MH/s with power consumption of 75W is a good substitute for RX

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470. However, the price has gone up in July 2017 from ~ $120 to ~ $150 if it is available to buy!

The problems with RX 560 4GB are:

1. RX 560 4GB requires a single 6-pin PCIE connector so it has similar requirement with RX 570 GPUs.

2. Although RX 560 requires 75W comparing to 125W of RX 570, but a smaller and lower wattage PSU can’t be used, why? Because you need PCIE power cables, a low wattage PSU for instant 750W one, does not have more four PCIE power cables.

3. While it occupies a PCIE slot, a six or seven GPU rig with RX 560 is weaker and has less hash power, while the same motherboard, SSD, CPU, RAM, chassis, etc. must be purchased. So, the GPU cost to total cost ratio is worse than the ideal RX 570.

Well, as RX 560 generates less heat, it does not necessarily require a beefy cooler and dual or triple fan. A Single fan cooler works well too.

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6.5.2. Nvidia GPUs

Well, the Nvidia 10s series GPUs are efficient, as GPU Showdown chart indicates, 1050ti and 1060 stand neck to neck with AMD’s. However, they are more expensive relative to the AMD rivals, and not many people would consider them a practical GPU mining option until AMD cards got out of stock in June 2017. Make the long story short, everyone turned to buy 1050ti and 1060 GPUs. GTX 1070 and 1080 are not so attractive because of their selling prices, making them totally undesirable option for a GPU mining rig.

The good thing about Nvidia 10s series card is they overclock very well while being stable too. My MSI Geforce GTX 1060 Aero ITX 6GB card mines ~ 21.60 MH/s with 1000MHz overclock on memory and 100 MHz on GPU core, while the stock clocks are 1759 MHz boost core clock and 8008 MHz memory clock. The temperature stays below 60C with 50% fan speed even with a tiny heatsink and single cooler. On the other hand, you also can decrease the power limit by about 50%, to ~ 80W and still mining rig does not blink once.

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However, I don’t recommend buying a GTX 1060 3GB card while the memory is not enough for continues mining operation by end of 2017. Besides it has less GPU CUDA cores comparing to 6GB cards, 1152 units to 1280 units.

1050ti is a unique card, the power draw is so low and it does not have a PCIE power connector and it gets all ~ 70W from the PCIE slot. After overclocks and adjusting the power limit, it mines ~12-14 MH/s and draws power of 50W-60W only. This performance, combining with the price of ~150$ makes it extremely efficient for a GPU mining rig, the only remaining problem is occupying one PCIE slot for a GPU, and consequently seven or eight GPU mining rig won’t be so powerful. The tricky part with 1050ti is, it would draw all the power it requires through the PCIE riser card, and between 50W-75W is relatively high-power draw from the slot. Power supply of the rig may not support all of the risers, or riser may fail eventually under pressure.

The rest of Nvidia line up, GTX 1070, 1080 and 1080ti don’t offer a good performance ratio, specially price to performance ratio. While on the net, some build mining rig based on high-end Nvidia cards, but economically they have much weaker return on investment comparing to smaller brothers.

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