Which power supply for a Bitaxe? When the standard one is enough and when an upgrade pays off

The power supply is the least glamorous component of a Bitaxe – and the most common cause of restarts nobody can explain. The good news: every miner from our shop ships with the matching supply, and whether it is enough shows in a single number in AxeOS. This article gives the values for every model, the connector, the check value and the cases where a stronger supply actually helps.

Which device needs which power supply?

The most important point first, because it goes wrong most often: not every miner runs on 5 volts. The single-chip boards do; everything from the Bitaxe GT upwards needs 12 volts. A 5 V supply on a 12 V device simply will not start – the other way round, a 12 V supply destroys a 5 V board. These are the values the devices ship with from us:

The connector is the same on every Bitaxe and Nerd device: a 5.5 × 2.1 mm barrel plug, positive inside. So a third-party supply fitting mechanically says nothing about the voltage – a 12 V router supply has exactly this plug. The USB-C port does not power the miner; it is only for flashing and the serial console.

The one check value: input voltage in AxeOS

You do not have to guess whether your supply is enough. The AxeOS dashboard shows the input voltage under “Power” – what actually arrives at the board. On 5 V devices 5.0–5.2 V is normal. If the value drops below 4.8 V under load, the supply or the cable is too weak: the voltage regulator does not get enough to hold the ASIC voltage, the chip computes unreliably, the hash rate error rises, and every load peak restarts the miner. On 12 V devices the same applies below 11.5 V.

A Gamma draws around 3 A at factory settings – so the 6 A supply has twice the headroom. It only gets tight when you overclock (at 625 MHz / 1250 mV it is around 5 A) or when a thin, long cable sits between supply and miner. Restarts that seem to come out of nowhere almost always have this cause; the troubleshooter asks exactly that first.

More headroom yes, more voltage no

Two things are often confused with power supplies: power and voltage. A supply with more amps never hurts – the device takes what it needs, the headroom stays unused. A higher voltage, on the other hand, destroys the board. So for every replacement the order is: first the voltage exactly as in the table, then enough current with headroom, then the connector. Never buy by plug shape.

Several miners on one supply

If you run two or three 5 V devices, you can combine them on one central supply. The standard unit for that is the Mean Well LRS-100-5: 5 V, up to 18 A, 90 W. The maths: three Gammas at factory settings draw around 9 A together, overclocked up to 15 A – that fits with headroom. Three overclocked devices at the limit would be 18 of 18 A, with no margin at all; properly sized are two overclocked or three factory Gammas per LRS-100-5. Every miner gets its own lead to the supply (no daisy-chaining), at least 1.0 mm² cross-section, and the unit needs air because it has no fan.

For 12 V devices the counterpart is the LRS-150-12 (12 V / 12.5 A) for one NerdQaxe++ with headroom or the LRS-350-12 (12 V / 29 A) for several. With one or two miners, though, the supplied unit is the simpler and equally reliable solution – a central supply only pays off when the setup is meant to run permanently and tidily.

When an upgrade makes sense

• Overclocking: from about 600 MHz a Gamma draws more than 4 A. The 6 A supply can do that, but without the 30 % margin – an LRS-100-5 or a 5 V / 8 A plug-in supply gives it back.
• Several miners: see above.
• Long or thin cable: every metre of cable costs voltage. Better to move the supply next to the miner than to extend the cable.
• Input voltage below 4.8 V: the supply is either faulty or undersized – replace it in both cases, do not tolerate it.

An upgrade is not sensible because “more watts bring more hash rate”. The hash rate depends on the ASIC clock and voltage you set in AxeOS – the supply only has to deliver them stably. How far you can go is in the overclocking guide.