I have one “bad” Antminer U1. Well… bad… at stock Freq it runs fine, when I tune it to 0981 it has about 30% hardware errors. Time for some research and tune up. I took off the cooling plate with the antminer logo. There is no cooling pasta between the plate and the PCB but some kind grey rubber something. Must be conducting too I guess but threw it away. First I wanted to fit a huge CPU cooler from an old Dell PC but it’s a little overkill. I had an alumium heatsink, cut a bit off with a saw. Drilled two holes in it for the screws. Applied some thermal paste, fitted the heatsink and tightened the screw. Applied the Antminer cooling plate just for the looks.
Some new gadgets, USB Antminer U1 SHA-256 Miner @ 1.6 to 2.6 GHS (with OC). These are not supported yet by the standard miningsoftware, used a modified cgminer, you can get it here: https://github.com/AntMiner/AntGen1. I put 5 Antminers in a Rosewill 10port Hub, put a 12x12cm Fan in front of it and fired it up. Tested some settings to get the best performance:
./cgminer --bmsc-options 115200:20 --bmsc-freq 0781 -o YOUR POOL URL -u WORKERNAME -p WORKER PASSWORD
with these setting you get stock hashrate of 1600MHs
./cgminer --bmsc-options 115200:20 --bmsc-freq 0881 -o YOUR POOL URL -u WORKERNAME -p WORKER PASSWORD
with these setting you get stock hashrate of 1600 to 1800MHs
./cgminer --bmsc-options 115200:20 --bmsc-freq 0981 -o YOUR POOL URL -u WORKERNAME -p WORKER PASSWORD
with these setting you get stock hashrate of 2000MHs. One strange thing with options 1 Antminer gets very much HW-error, the other 4 work fine.
Please be aware when you overclock them warranty will void (terms of us from the manufacturer) and you always should use proper cooling. The standard factory setting is bmsc-freq 0781.