Mining Ready PSUs

We initiate a new program, through which we find the most suitable PSUs for mining or in general highly stressful applications where besides high efficiency, high performance and increased reliability are also required.

Most of you have probably heard of Bitcoin, the coin that initiated the mining frenzy. Currently there is a great number of crypto currencies and it is still profitable to mine some of them using a plain desktop PC instead of using a special ASIC (Application-Specific Integrated Circuit). Briefly mining is a record-keeping service which demands of huge processing power, leading miners who use PCs for this process to take advantage of the raw power that GPUs provide instead of utilizing the system’s CPU(s). The problem is that GPUs have to operate under full load conditions highly stressing the power supply (PSU). We should stress here however that even ASICs (like the popular Antminer systems) use normal, desktop PSUs. So besides a highly efficient PSU, in order to keep the electricity cost as low as possible, you also need a reliable unit which will be able to operate 24/7 under highly stressful conditions without sweating. As expected the PSU’s noise doesn’t concern miners since most crypto-currency farming facilities operate in dedicated spaces where the operators don’t have to stay long; even home miners should install their mining systems in isolated spaces, where noise won’t be a problem. As a matter of fact, in PSUs used for mining purposes the fan is expected to operate close to its full speed most of the time, given the high load output, effectively cooling down sensitive components which dramatically affect a PSU’s reliability (e.g. the electrolytic capacitors of the secondary side). 


Our purpose isn’t to torture test each and every PSU that a manufacturer sends for certification since we already do this in our 10-110% load tests (conducted in the ETA certification), during which we overload the PSU with the ambient temperature exceeding 45°C, but mostly to examine closely its components in order to find out whether it will survive on the long run. For example a PSU with a bulk cap which is rated at 85°C will have a significantly shorter lifetime compared to a PSU with a 105°C rated bulk cap. The same applies of course to the filtering capacitors on the secondary side. A PSU that uses low quality filtering capacitors with 1-3,000 hours lifetime under 105°C won’t last as long as a PSU that uses 6-10,000 hours caps rated at the same temperature. Another important factor is the cooling fan, since if the fan breaks down then the PSU will most likely follow immediately, especially if it doesn’t have Over Temperature Protection. We only accept double ball-bearing fans as suitable for mining PSUs, because all FDB/HDB and other sleeve variant bearing fans won't survive long enough under very high operating temperatures (>45°C). 


In order to provide a Mining Ready certification we expect a PSU to meet all of the requirements listed below. The ideal mining PSU should also meet our recommendations.

  1. [Requirement] 1 kW or higher capacity.
  2. [Requirement] ETA-B and higher efficiency certification.
  3. [Requirement] Lower than 50mV ripple at +12V under full load at increased operating temperatures (>45°C).
  4. [Requirement] Quality fan with double ball-bearings.
  5. [RequirementTwo EPS connectors.
  6. [Requirement] For PSUs with up to 1.1 kW capacity the minimum number of  6+2 pin PCIe connectors is six. For PSUs with over 1.1 kW capacity the number of minimum 6+2 pin  PCIe connectors is eight and for PSUs with over 1.45 kW capacity the minimum is ten 6+2 pin PCIe connectors
  7. [Recommendation] Dedicated cables with 6+2 pin PCIe connectors are preferred. In case a cable hosts two PCIe connectors, it needs to have 16AWG gauges up to the first connector for the six out of the eight pins at least. 
  8. [Requirement] At least four 4-pin Molex connectors on more than two cables in 1 kW and stronger PSUs and six 4-pin Molex connectors in three or more cables for 1.45 kW and higher wattage PSUs.  In case the PSU has more than ten 6+2 pin PCIe connectors we are covered with four 4-pin Molex connectors on two cables in any case. 
  9. [RecommendationIdeally the peripheral connectors should have 15cm distance between them.
  10. [Requirement] All peripheral cables should use 18AWG wires minimum.
  11. [Requirement] For 1.4kW and stronger PSUs a C19 coupler is required, while an AC power cord with 14AWG wires should be used. For lower capacity PSUs an AC power cord with 16AWG gauges at least is required. 
  12. [Recommendation] Ideally every PSU with 1.2kW or more capacity should use a 14AWG power cord along with a C19 coupler.  
  13. [Requirement] The essential protection features (SCP, OPP) including Over Temperature Protection.
  14. [Requirement] Over 18ms hold-up time and an accurate power ok signal.
  15. [Requirement] Complete EMI filtering stage (minimum components: 4x Y caps, 2x X caps, two CM chokes, an MOV) along with inrush current protection (an NTC thermistor is required which ideally should be supported by a bypass relay).
  16. [Requirement] Impeccable build quality including quality MOSFETs, high quality bulk and filtering capacitors (105°C and the majority of filtering caps on the secondary side much have higher than 5,000h lifetime). The use of polymer caps on the secondary side is preferred. 
  17. [RecommendationOne year minimum warranty for 24/7 operation under full load at 35-40°C

We plan to create a separate database for Mining Ready PSUs, once we have enough data at our disposal to support it. Meanwhile we will only provide this information on demand. 

We expect the mining community to help us improve/upgrade our requirements for a Mining Ready PSU. If you have any suggestions or a new test in mind in order to feel more confident about your next PSU purchase, feel free to share your thoughts with us at info@cybenetics.com. Finally, if you own a mining facility and you are concerned about your next PSU order, you can send us samples of the candidate PSUs. We will thoroughly test them within a short period, suggesting the best options given your demands.