I have been exploring the fascinating world of cryptomining over the last few days and found that along with the big and expensive rigs (Antminers etc) that cost a fortune there are also some miners that are connected by USB. Does anyone have experience with these devices? I would be really interested in trying them out  

Edit: forgot to add earlier - if anyone has experience with these, how much power to they use and do they use CPU/RAM of the computer?