PSU Efficiency
PSU efficiency is the share of wall watts that actually reaches the chips. The rest turns into heat right inside the power supply, before any mining happens.
Where the percent points go
Server power supplies in ASICs hold efficiency around 93 or 95 percent at working load. Sounds close to ideal, but at 3300 W from the wall even 94 percent means about 200 W of pure heat inside the supply itself: a small space heater built into the ASIC.
Efficiency is not a constant, it depends on load and on line voltage. A supply shows its best numbers in the middle of its load range and its worst at low load. And nearly all power supplies in modern ASICs are designed for 200 or 240 volts: on low voltage they lose efficiency, cut power or refuse to start at all.
You pay for the losses twice: first as kilowatt-hours the chips never saw, then as heat that in summer also has to be removed. So the supply's efficiency sits inside the ASIC's total J/TH, it just never gets its own line in the specs.
An aging supply loses efficiency quietly: dust, dried-out capacitors, tired fans. The ASIC runs, the pool numbers stay the same, yet the meter spins faster. A supply case running hot and its fan stuck at full speed is a call for maintenance.
The short version
| Typical efficiency | 93 or 95 percent at working load |
| Losses at 3300 W | about 200 W of heat in the supply |
| What it depends on | load and line voltage |
| Working voltage | 200 or 240 volts, lower is worse |
| Sign of decline | the supply runs hotter at the same watts |
How to stop wasting watts
Feed the supply proper voltage: a 230 volt line with no sag. Extension cords and thin cables steal volts and heat up themselves.
Keep the supply clean along with the ASIC: dust in its heatsinks hits efficiency the same way it hits the chips.
When undervolting, remember the load curve: a supply in the middle of its range runs at its sweet spot, a small bonus of eco modes.
When replacing, don't chase a cheap clone: savings on the supply come back as a power bill and hashboard repairs after it dies.
An example in numbers
An ASIC draws 3300 W from the wall. At 94 percent efficiency about 3100 reaches the chips, while 200 W heat the supply itself. Over a month those losses rack up about 144 kWh: you pay for them at your rate, though they brought not a single hash.
Related terms
Where to go next on the site
Hardware
- ASIC Miner knowledge base
Numbers
Questions and answers
Can I run an ASIC on 110 volts
Stock power supplies of modern ASICs on such a line either refuse to start or cut power. They want a 200 or 240 volt line, and you check that before buying, not after.
Is it worth swapping a healthy supply for a more efficient one
For a percent of efficiency usually no, the difference doesn't pay for the supply. Swap a degraded one: overheating, noisy, with sagging output voltage.
Why did my ASIC start drawing more at the same hashrate
The supply is one of the suspects: dust and age drag efficiency down, and the extra watts go into heating it. Check the supply's case temperature and its fan.
How the terms connect
Every link in the chain is clickable. Orange marks where you are now.
Looking for an ASIC miner
The catalog holds 212 models. You can compare them by hashrate and by joules per terahash, then plug your own rate into the calculator and see what stays in your pocket.
Page written and checked by Denys Klimchuk. Updated .