1.6 GH/s – 0.405A
1.8 GH/s – 0.456A
2.0 GH/s – 0.505A
2.2 GH/s – ~~~~~~
As soon as you fire up cgminer or another compatible mining software and the AntMiner U1 starts working at 1.6 GH/s the power consumption increases significantly that what you get in idle mode. At first we’ve measured 0.385A current used or about 1.925 watts – a bit below the manufacturer’s rating, however this is the power usage while the device is still cool. Just a few minutes later since everything gets hotter (thermal images) after the AntMiner U1 starts operating and the power usage increases along with the temperature of the chips. In just about 10 minutes after starting to mine with the device the current usage increases to 0.405A or a total of 2.025W of power, something that does not seem that much higher at first, but as you start to overclock the device you will notice that the gap between a well cooled AntMiner U1 and a very hot miner increases. The problem is that the higher power consumption leads to more heat and can also result in less performance when overclocking.
Here are the results we’ve got as a power consumption of the AntMiner U1 device connected on a USB 2.0 port. Have in mind that USB 2.0 ports have a standard limit on maximum current they can provide to a connected device of 0.5A or 2.5W in total and this can lead to lower performance you can get when overclocking as you might be hitting the interface power limit and not the device’s: