Without power, the farm does not produce cryptocurrency. A regular power supply without labels or identification marks will do a great job of burning cards or blowing fuses under 24/7 load. Let's figure out how to choose a power supply that won't burn down the farm and will work for a long time and reliably.
To give practical advice on choosing a power supply, the editors of Hashalot enlisted the opinion of an expert . Key recommendations for choosing a power supply were given by Pavel Zhuklinets, founder and head of the company MinerTech , which has been producing server power supplies for mining farms since 2013.
Producer groups
- OEM (Original Equipment Manufacturer) – companies that design and manufacture units.
- Companies that do not have their own production, these companies can develop the design or software, but OEM partners produce blocks for them. Such companies include: Corsair, Be Quiet, SilverStone. For example, for Corsair the OEM of the HXi series power supplies is CWT.
- And the third category is TradeMark (™) companies, they simply label the purchased products with their own brand and resell them on the market, perhaps slightly changing the design of the radiator.
In our case, we will choose power supplies from 750 watts and above. To run one farm with 5 video cards from Sapphine Nitro+ RX 480 8GB, we need one good 1200-watt power supply, or two 750-watt power supplies.
Criterias of choice
- Power supplies must have at least 4 PCI-e (6/8 Pins) connectors.
- Power supplies must have minimum protection: OPP, SCP, OVP. As a rule, all modern power supplies come with protection.
- The power supply cables must be made according to the AWG18 standard, this is indicated on the power supply cables; anything thinner (AWG20/22) is not suitable! (American wire gauge, the lower the number, the thicker the wire). As a rule, all modern power supplies come with cables of this caliber.
- The power supply package includes the required number of all cables.
Precautionary measures
The server power supply is not typically user serviceable. Never open the casing of this device. It contains capacitors that can hold a strong electrical charge even if the computer is turned off and unplugged for a week. This is especially important when pinouting a server power supply. You can protect your equipment from power surges using surge protectors and uninterruptible power supplies.
Efficiency of power supplies and consumption from the outlet
Efficiency - efficiency, a characteristic of the efficiency of a system in relation to the conversion or transmission of energy.
The efficiency of power supplies, or operating efficiency, determines how much the unit consumes from the outlet. For example, a farm consumes 1000 watts with a unit efficiency of 85%, this means that 1150 watts are consumed from the outlet. Below is a table of the efficiency of power supplies depending on the certificate and power consumption. It is not recommended to take a power supply without a certificate; it is better to take one from Silver and higher.
For the reverse situation, when we need to calculate the actual consumption of a video card or farm when using a watt meter, we subtract 15% of the reading from the watt meter.
For example, on a watt meter we see the consumption of 1150 watts, subtract 10-15% and get the consumption of the farm itself.
| Certificate | Load (from max. power) | |||
| 10% | 20% | 50% | 100% | |
| 80 PLUS | — | 80% | 80% | 80% |
| 80 PLUS Bronze | — | 81% | 85% | 81% |
| 80 PLUS Silver | — | 85% | 89% | 85% |
| 80PLUS Gold | — | 88% | 92% | 88% |
| 80PLUS Platinum | — | 90% | 94% | 91% |
| 80 PLUS Titanium | 90% | 94% | 96% | 91% |
In addition to the certificate, an important indicator is the 12V line. As a rule, if the power supply is certified Gold or higher, then the declared power of the power supply, for example, 750W, corresponds to the power along the 12V line. And since the farm will mainly use only this line (12V), it is necessary that the output power corresponds to the declared one.
Examples of cheap power supplies with discrepancies in declared power
BitFenix Fury 750W 80 PLUS GOLD
APEVIA WARLOCK ATX-WA750W
As can be seen from the example above, for the BitFenix block the output number of watts is 720 (12*60).
And for the Apevia block, at the output we will get 576 watts (12*48) out of 750 declared.
In power supplies, the 12V lines can be divided, there can be 2/3/4 of them - this must be taken into account. Since within the same power supply, if a video card and a riser are connected, then they must be connected to the same line, and not different! To do this, you need to look at the technical documentation to understand which connectors are connected to which lines. The same thing applies if there are two power supplies, you cannot connect the riser to one unit and the video card to another. We need the power supply to have only one 12V line. For a 1200W unit, the characteristics should indicate: “+12V: 100A”, multiply the amperes with volts, and get the power of the power supply on the 12V line.
Example of a power supply with several 12V lines
Example of a power supply with one 12V line
Do not forget that cheap power supplies, for example from brands such as Aerocool, can seriously sag at full power, and out of the declared 1000/1200 watts, produce 800. In this case, such units cannot be used for assembly in a farm. Especially if the assembly consists of only one power supply.
Cleaning and Maintenance
Due to the constant operation of the power supply fan, it forces a large amount of air through its case. This dust-containing air clogs the power supply case over time, which significantly worsens its temperature. May cause fire or malfunction. To avoid wasting time on repairs, it is advisable to periodically clean them. By blowing, and in case of heavy contamination by disassembling and cleaning with an antistatic brush.
Weekly purging is mandatory. To avoid spending a ton of money on cans of compressed air, buy an electric leaf blower. But no matter how hard you try, dust will still settle and stick, so sooner or later more thorough cleaning will be needed.
If the device is still under warranty, then it is better not to open it yourself, but contact a specialized service center. As they say: “Cleanliness is the key to health,” and in this case, the key to timely receipt of profit.
CHIEFTEC A-135 750W (APS-750CB)
Connectors for graphics adapters: 6+2-pin 4 pcs.
Power: 750 W
Choosing a CHIEFTEC A-135 750W (APS-750CB) power supply when assembling a mining rack with four discrete graphics cards will be an excellent solution. This device is distinguished by a semi-modular design and the presence of only two soldered wires - for supplying power to the 8PIN processor (4+4) and for powering the 24PIN ATX motherboard. The remaining wires, which are nine SATA cables, four for additional power supply of 8PIN (6+2) PCIe video adapters, two with a Molex connector and a Floppy cable, can be easily disconnected if necessary.
The component in question has two twelve-volt output lines, each of which received a current of 35 Amperes. The power supply also has 3.3V and 5V lines of 25 Amps each.
Among the main advantages of the CHIEFTEC A-135 750W (APS-750CB) power supply:
- operation with an efficiency factor of over 85% (thanks to this parameter, the power supply unit received an 80 PLUS Bronze certificate);
- almost silent cooling system, including a 140 mm fan with automatic speed control;
- reliable protection systems against overvoltage and undervoltage, overloads, overheating, short circuits;
- The average duration of uninterrupted operation of a power supply is one hundred thousand hours.
CHIEFTEC A-135 1000W (APS-1000CB)
Connectors for graphics adapters: 6+2-pin 6 pcs.
Power: 1000 W
The CHIEFTEC A-135 1000W power supply (APS-1000CB) is a powerful component that can simultaneously power a mining farm of six discrete graphics adapters. Like the device above, this power supply is awarded 80 PLUS Bronze certification due to its high efficiency value of about 85%. Among the advantages of the component is also a low-noise cooling system with a 140 mm fan, which rotates at a speed controlled by a special intelligent system.
Thanks to the semi-modular design, all the main cables supplying power to the 8PIN (4+4) processor, 24PIN ATX motherboard and 8PIN (6+2) PCIe connectors in the block are routed directly from the case. Additional wires - MOLEXx2, SATAx9, PCIex4 and Floppy - can always be disconnected if desired.
The power of the twelve-volt line of the CHIEFTEC A-135 1000W (APS-1000CB) power supply is 996 W, and the 3.3 V and 5 V lines are about 140 W. The features of the component in question are also the presence of protection against power surges, short circuits and excessive heating of the device, which is very important in the process of continuous mining of cryptocoins.
RAIDMAX Scorpio 1000W (RX-1000AP-S)
Connectors for graphics adapters: 6+2-pin 4 pcs.
Power: 1000 W
The large bright blue fan of the cooling system gives the RAIDMAX Scorpio 1000W (RX-1000AP-S) power supply a special originality. Among the main advantages of this device is its high level of efficiency, which served as the basis for obtaining the 80 PLUS Bronze certificate. The unit is equipped with a twelve-volt line with a current of 82 Amps, which provides it with a power of 984 W, and 3.3 V and 5 V lines with a current of 20 Amps each.
The advisability of using this power supply when assembling a mining farm is due to the presence in it of:
- four removable 6+2-pin cables for powering discrete graphics cards;
- 20+4 pin cable for supplying power to the motherboard;
- 4+4 pin cable for powering the processor.
Distinctive features of the component are:
- support for power saving modes for processors with Haswell microarchitecture;
- intelligent fan speed control system;
- Supports various methods of protection against overloads, overvoltage, short circuits, etc.
RAIDMAX Cobra 1200W (RX-1200AE-B)
Connectors for graphics adapters: 6+2-pin 6 pcs.
Power: 1200 W
The RAIDMAX Cobra 1200W power supply (RX-1200AE-B) is ideal for a mining rack of six discrete video adapters. The energy efficiency of the device is confirmed by a high level of efficiency, for which it received an 80 PLUS Gold certificate. The individuality of the style of the component is given by the body with an original design and ventilation grilles made in the shape of a honeycomb.
The only two cables that cannot be disconnected from the case of the power supply in question are the two power supply cables to the processor 4+4 pin and the cable connecting to the motherboard 20+4 pin. The removable cables include six with a 6+2-pin interface for PCI-E connectors, nine SATA, six MOLEX and one Floppy. All cables are distinguished by the presence of high-quality plastic braiding.
In operation, the RAIDMAX Cobra 1200W (RX-1200AE-B) power supply is capable of reaching its maximum power of 1200 W on a twelve-volt line at a current of 100 Amps, but is also equipped with 3.3 V and 5 V lines with a current of 20 Amps.
The component in question has received all the necessary protection systems, including from overloads, so it is excellent for long-term operation under constantly high loads, which is necessary in the case of cryptocoin mining.
It cannot be said that only among the power supply models listed above is it worth choosing when assembling a mining rack, since you can find other devices on the market that are no less suitable for the purposes under consideration. However, for novice enthusiasts who want to try themselves in a new type of income, the power and characteristics of these components will be quite enough. Although many experienced miners consider it more advisable to use power supplies from our TOP selection rather than buy more expensive models, which in terms of characteristics are not particularly superior to those considered.
Connectors
It is important to check how many and what connectors are present on the power supply, examples for different units.
EVGA Supernova
Cooler Master V1200
As can be seen from the example above, for different power supplies, the number of connectors, as well as the connectors themselves, can differ significantly.
Performance indicators
As of 2012, some high-performance consumer power supplies can exceed 90% efficiency at optimal load levels, although will drop to 87-89% under heavy or reduced loads. Google server power supplies are more than 90% efficient. Hewlett-Packard achieved 94% efficiency. Standard batteries sold for server workstations are 90% more efficient than in 2010.
Energy efficiency decreases significantly at low loads. Therefore, it is important to check the server power supply and match the power of the source with the needs of the computer. Efficiency usually peaks at around 50-75% load.
Connecting 2 power supplies or more
Option #1. We use a synchronizer
Synchronizer
- SATA connector connected to the master power supply.
- 24pin connector for connecting a slave power supply.
- Synchronization mode switch, On/Off.
- Molex connector - DO NOT USE!
Option #2. We use a MOLEX connector
Molex connector
We supply power from the master power supply to the Molex connector, and connect the slave power supply to the 24pin connector.
There is a version with a SATA connector.
Option #3. Connect using Dual PSU Power Supply Extension Cable
Dual PSU Supply Extension Cable
- We connect it to the motherboard.
- We connect to the main power supply.
- We connect it to the slave power supply.
Connecting using a cable is inferior to synchronizers, since the cables may not be AWG18, but AWG20, even if they are marked as 18. When connecting using synchronizers, original high-quality cables from power supplies will be used.
Option number 4. We use a “paperclip” (not recommended if you don’t know what to do)
I recommend looking at the possibility of purchasing two power supplies of 750 watts or more, since finding a good power supply from 1200 watts at a reasonable price is now very difficult, they are simply not in stock, you can only pre-order and wait, and units of lower power are in stock and connecting from two blocks through synchronization is more practical than from one block.
Also, from two power supplies we can get more cables than from one 1200W unit.
It is also worth noting that if one of the blocks fails, the farm will not stop mining, but will only operate at less than full capacity.
When using two blocks, both blocks with the same power and blocks with different power are allowed, for example, the master can be 850 watts and the slave 750 watts.
External equipment
Power supplies are rated by power and show how much power they can provide to a computer. Since every computer part requires certain conditions to function properly, it is important to have a server power supply that can deliver the required performance. There is a convenient cooler supply calculation tool that can determine the necessary parameters.
There are also external power supplies that are connected separately using a power cable and can reduce the appearance of the PC system.
Server power supplies
Among the possible disadvantages of using such blocks at home, I can note:
- High noise level.
- Dubious warranty from the seller. Compared to the 7/10/12 year warranty of a conventional power supply.
- Questionable certification; the effectiveness of such units may be far from ideal.
- Doubtful possibility of sale on the secondary market, except to the same miner.
- You may have to solder the necessary outputs yourself; be sure to agree in advance on the required number of Molex, 6pin, etc. outputs.
- In most cases, you purchase used power supplies; this point must be clarified with the seller.
Based on the above criteria, I can recommend using such blocks only if you are aware of all aspects of the decision being made.
| PSU name | Power W | SKU | OEM |
| Number of video cards - 3 | |||
| Corsair HX | 750 | CP-9020137-NA | C.W.T. |
| Corsair RMx | 750 | CP-9020092-NA | C.W.T. |
| Seasonic Prime Gold | 750 | SSR-750GD | Seasonic |
| Seasonic Prime Platinum | 750 | SSR-750PD | Seasonic |
| EVGA SuperNOVA G2 | 750 | 220-G2-0750-XR | Super Flower |
| EVGA GQ | 750 | 210-GQ-0750-V1 | FSP |
| Number of video cards - 4 | |||
| Corsair HX | 850 | CP-9020138-NA | C.W.T. |
| Corsair RMx | 850 | CP-9020093-NA | C.W.T. |
| Seasonic Prime Gold | 850 | SSR-850GD | Seasonic |
| Seasonic Prime Platinum | 850 | SSR-850PD | Seasonic |
| EVGA SuperNOVA G2 | 850 | 220-G2-0850-XR | Super Flower |
| EVGA SuperNOVA GS | 850 | 220-GS-0850-V1 | Seasonic |
| EVGA GQ | 850 | 210-GQ-0850-V1 | FSP |
| Cooler Master V850 | 850 | RS850-AFBAG1 | |
| Number of video cards - 5 | |||
| Corsair HX | 1000 | CP-9020139-NA | C.W.T. |
| Corsair RMx | 1000 | CP-9020094-NA | C.W.T. |
| Seasonic Prime Gold | 1000 | SSR-1000GD | Seasonic |
| Seasonic Prime Platinum | 1000 | SSR-1000PD | Seasonic |
| EVGA SuperNOVA G1 | 1000 | 120-G1-1000-VR | FSP |
| EVGA SuperNOVA G2 | 1000 | 120-G2-1000-XR | Super Flower |
| EVGA GQ | 1000 | 210-GQ-1000-V1 | FSP |
| EVGA SuperNOVA GS | 1050 | 220-GS-1050-V1 | Seasonic |
| Cooler Master V1000 | 1000 | RSA00-AFBAG1 | |
| Number of video cards - 6 | |||
| Corsair HX | 1200 | CP-9020140-NA | C.W.T. |
| Seasonic Prime Gold | 1200 | SSR-1200GD | Seasonic |
| Seasonic Prime Platinum | 1200 | SSR-1200PD | Seasonic |
| EVGA SuperNOVA G2 | 1300 | 120-G2-1300-XR | Super Flower |
| Cooler Master v1200 | 1200 | RSC00-AFBAG1 | Seasonic |
As you can see from the table presented, the choice of power supplies is huge.
Examples of choosing power supplies for assembling a farm
So, we have several tasks, using the example of which we will consider approaches to choosing a power supply, using the example of units from SeaSonic, Prime series.
Task No. 1: Assembling a farm of 4 1060 series video cards
Let's say we want to assemble a farm of 4 video cards, for this we need to know:
- consumption of 4 video cards 120W*4 = 480/500W + System consumption = 65W;
- These video cards have only one 8-Pin power connector;
- to connect we need: our power supply must have the following number of connectors: 5 connectors for peripherals, 4 connectors for video cards, one connector for the processor (CPU or PCI-e);
- one Sata cable for connecting SSD/HHD;
- two Sata cables for connecting risers;
- two Molex cables, which, depending on the manufacturer of the power supply, are connected to peripheral connectors;
- at least 4 PCI-e cables, for connecting 4 video cards.
In terms of power, we are suitable for units from 650W, for connectors from 750W, and for a set of cables from 850W.
Selection of blocks according to the required parameters:
- a 650W block is not suitable due to the presence of only 4 PCI-e inputs, one of which will be occupied by the CPU (these CPU and PCI-e blocks have combined connectors);
- the 750W unit is not suitable because it comes with only two PCI-e cables, as well as one Molex and two Sata;
- an 850W unit is suitable because: we install 3 video cards on the 3 PCI-e cables supplied in the kit;
- on 3 Sata cables supplied in the kit, we install 2 Sata risers and HDD/SSD;
- for 2 Molex cables supplied in the kit, we install 2 Molex Riser;
- For the remaining video card, we will use one additional CPU cable, on which we will install a CPU>PCI-e adapter.
Task No. 2: Assembling a farm of 5 1070 series video cards
- consumption of 5 video cards 175W*5 = 875/900W + System consumption = 65W;
- These video cards have one 8-Pin power connector or 8+6-Pin;
- for connection it is necessary: the power supply must have the following number of connectors: at least 5 connectors for peripherals, at least 6 PCI-e connectors (5xVGA + 1xCPU);
- one Sata cable for connecting SSD/HHD;
- two Sata cables for connecting risers;
- two Molex cables, which, depending on the manufacturer of the power supply, are connected to peripheral connectors;
- at least 4 PCI-e cables, for connecting 4 video cards;
- one additional CPU cable.
So, in terms of power, units from 1200W or a set of two power supplies for 850+750W are suitable for us.
- Selection of power supplies according to the required parameters:
- 650/750/850W units are not suitable due to lack of power;
- a 1000W unit is not suitable due to the lack of a power reserve of at least 10%;
- 1200W unit - suitable because; on 4 PCI-e cables supplied in the kit, we install 4 video cards;
- on 3 Sata cables supplied in the kit, we install 2 Sata risers and HDD/SSD;
- for 2 Molex cables supplied in the kit, we install 2 Molex Riser;
- For the remaining video card and riser, we will use one additional CPU cable, on which we will install a CPU>PCI-e 8+8-Pin adapter and use a six-pin riser.
Task No. 3: Assembling a farm of 6 or 8 video cards
To solve this problem, power supplies that are equipped with the required number of connectors and cables are suitable, or, which is simpler and more reliable, you need to use two or more power supplies in the assembly.
- Please note that high-power video cards, such as the 1080 series, use 8+8-pin power. And you need to connect both connectors, and most importantly, you need to remember that two cables and two connectors on the block will be used. This means that you won’t be able to connect more than 2 of these video cards to a 750/850W power supply!
- The main advantage of using two power supplies is the supply of CPU power cables that can be used in conjunction with adapters. In our case, we get three free cables, which can be used to fully equip six-pin risers, video cards, or a video card together with a riser, depending on the power of the card itself.
Correct power calculation
When calculating the power of a power supply for mining, it is necessary to rely on the fact that the processor, motherboard and hard drive will consume up to 150 watts. Outdated CPU models, on motherboards with AM3+ socket, themselves consume about 100 W. If you use a regular hard drive and not an SSD, then this is another 20-30 W, in addition to the motherboard itself another 40-50 W. That is, in principle, a mining rig “body kit” can consume as much energy as two 1660Supers. To save at least a little, never connect an audio system or extra USB connectors. The keyboard and mouse can also be disconnected after successful startup.
The biggest consumption during mining comes from the power supply circuits of video cards.
Each video card will consume (depending on the selected mining algorithm) the GTX 1060 level - up to 160-180 W, the R9 290 level - up to 300 W. Perhaps the most economical are Nvidia 1660Super graphics adapters. They can operate at a powerlimit of +70, or even +60, consuming no more than 120 watts. But you should take into account not only the nominal consumption, but also the ratio of hashrate to unit of energy.
AMD's Rx 400/500 series cards, popular in the past, are more power hungry. For mining on RX 580, 570, 480, 470 video cards, the power supply must have even more power. When dual mining Ethereum and Decred/Siacoin/Pascal, consumption can reach 150-180 watts (depending on the frequency and core power settings).
In each specific case, it is necessary to have a power reserve to ensure reliable long-term operation.
Thus, a system of 6 GTX 1660 video cards will consume about 1050 watts, which will require the use of a power supply with a power of 1200 watts or more.
If you use maximum downvolting and choose the least energy-intensive cryptocurrencies when mining, you can significantly reduce energy consumption and reduce power consumption, but you need to take into account that over time you will have to switch to mining another cryptocurrency that will require more power.
Based on the power consumption of video cards like GTX 1060, it is necessary to install the following power supplies:
- 1600-watt power supply for mining on 8 video cards;
- 1200-watt power supply for mining on 6 video cards;
- 1050-watt power supply for mining on 5 video cards;
- 900-watt power supply for mining on 4 video cards.
- For RX 470-580 video cards, the power reserve needs to be increased by 10 - 20%.
