PDU
A PDU is a power distribution unit: an industrial power strip with several heavy duty outlets, often with energy metering and remote power cycling.
What a PDU is
An ASIC pulls from the outlet nonstop, and household extension cords melt at those currents. A PDU is a rack or wall mounted strip with outlets rated for heavy loads, its own breaker and cable of the right gauge. Connectors on mining PDUs are usually C19 or C20, the same ones sitting on the miners' power supplies.
There are three levels. A basic PDU just hands out power. A metered one shows consumption for the whole strip or for each outlet. A switched one can turn outlets on and off over the network, and that is the feature people buy it for: a hung asic reboots from your phone instead of a drive to the site.
Capacity is counted per phase, not per outlet. A strip with eight outputs behind a 32 A breaker delivers about 7.4 kW, meaning two asics at 3500 W, and the other six outlets stay empty. Kilowatts are what you count, or the breaker will trip every evening.
Quick reference table
| What it does | hands out heavy duty power to several asics |
| Connectors | usually C19 and C20, as on the power supplies |
| Types | basic, metered, switched over the network |
| 32 A phase | about 7.4 kW, two asics at 3500 W |
| Why switched | reboot a hung asic without a site visit |
How to choose without overpaying
Start with the breaker and the cable, not with the number of outlets. A 32 A strip with eight outputs and a 16 A strip with eight outputs look identical and carry loads that differ by a factor of two.
Per outlet metering is more useful than it sounds: it shows that a miner's draw has dropped, which means a lost hash board, before the pool reports anything. Metering for the whole strip gives you no such picture.
Switched models cost more, and on one asic they are pointless: pulling the plug is easier. They start to make sense at three or four asics, especially if the site is not in your home.
Example
Six S21 asics at 3500 W each make 21 kW, so that is three phases at 32 A and three PDU strips, two asics on each. One contact in a power connector carries 8 to 9 amps, so connectors and cables get picked with headroom rather than right at the limit: the weakest joint in the chain is always the one that heats up.
Related terms
Where to go next on the site
Hardware
- ASIC Miner knowledge base
- Antminer S21 tool
Numbers
Questions and answers
Can you get by without a PDU
On one asic yes, if the outlet sits on its own circuit with its own breaker. With several asics a PDU keeps you from stringing together household extension cords that burn at these currents.
How many asics on one strip
Count by the breaker: 32 A is about 7.4 kW, meaning two asics at 3500 W. The number of outlets on the strip has nothing to do with it.
Is a PDU with power cycling worth buying
From three asics up, and especially at a remote site, yes: a hung miner comes back to life from your phone. For one or two it is money wasted.
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 .