Hey there.
I just bought 2 Antminer U3 to get in this topic "Bitcoin mining".

At the moment i'm running them on my desktop pc, just to figure out how it works.
After that i plan to run them on a raspberry pi.

But i've some problems with the GH/s.
One of them goes with ~55.. not the best but for the first i'm ok with that.
But the other guy only goes with ~15-20.
What's the problem with him?

They're running on USB 3.0 withount any hub, the standart psu (that thing they're delivered with) and cgminer 4.9.0. I've also tried version 4.8.0 - the same.
I've changed the USB Ports and the PSU to figure out if there is maybe a problem. But it's allways the same Unit who works so low.
Just when i start cgminer both work with the same speed, but after a few minutes one guy goes down.



edit: tried out version 4.9.2 - looks like the problem is solved!