Extra info:
Left it run for the night, come back the following morning, U3 isn't running. Go and have a look, seems that the power brick burnt out. After getting in contact with the store, they tell me that the frequency was set too high and that's why it was running slow and overheated the power block. Since I see no way to set the frequency in Minera, he recommended me to use MinePeon, or directly from the PC.

My thing is, I tried using MinePeon once, but the Rockminers don't seem to like the environment and thus don't work.

Any ideas people? The guy from the store recommended for me to use it via the PC otherwise, but then that defeats the purpose of me having the Raspberry Pi...

Good day,

I have a Raspberry Pi running Minera, and selected CGminer 4.x as the running miner. I had 2 Rockminers running (37GH/s ea), and recently added an Antminer U3 (63GH/s). The Rockminers each generate fairly close to what they advertise, running at 30GH/s each, but the Antminer U3 only generates 28GH/s. In other topics people were talking about different settings they use with the exe program, but as I am using the miner on a Rasp. Pi, I can't use these settings. So was hoping for anyone to give me advice on what I can do to get more out of the Antminer. I tried switching the miner prog from CGminer to BFGminer, but then none of the ASIC miners are recognised.

I am currently using the supplied power brick, I have tried it with computer psu but no difference in speed hash rate.
http://s7.postimg.org/rp01h5xij/Screen_Shot_2015_01_29_at_01_17_58.png