did not see the [antminer] tuning setting.
So how did you do it??
In bfgminer I set the clock to --set-device antminer:clock=x0981
the Antminer remembers the setting in the BitMinter client
Just installed bfgminer (on Mac OS X 10.9.2 using the Linux instructions) and successfully set the clock to 2.0 GH/s.
git clone https://github.com/luke-jr/bfgminer
cd bfgminer
./autogen.sh
./configure
make
make install
sudo ./bfgminer --scan antminer:all -o mint.bitminter.com:8332 -u USERNAME -p x --set-device antminer:clock=x0981
After it runs a few seconds you can type 'q' to quit bfgminer and re-start BitMinter with your AntMiner U1 devices set to 2.0 GH/s.
I was getting NO hardware errors at 2.0 GH/s so I tried 2.2 GH/s (clock=x0A81). That got a few hardware errors on four of my AntMiners but LOTS of errors on the fifth. I switched them all back to 2.0 GH/S. In theory you can use bfgminer to set them individually... maybe another time.