I'm running 3 BE's and AntMiner U1 - total ~3GH,
I have the cheapest i5 cpu - it's running on 80-100%,
Is this normal for such low hashing power?
Not sure, but for comparison's sake I have an i5 at 4ghz and am hashing with a BFL Jally at 6.4gh/s. My cpu usage is between 15% and 40%.
On another machine I have 3BE's and a Phenom x4 925 running at 3.2ghz and my cpu usage there is about 15% to 30%.
Hope that helps.
I had 3 bfgminers running,
1 - with 3 BEs
2 - 2nd gen with proxy running with http-port
3 - BTC bfgminer connected to the 2nd one running 1 Antminer U1
each one of them is taking 20-30% cpu...
So i combined 1 + 2, and 3 is connected to them with proxy, seems like 60% now

still a lot but better