I can modify your miners for you if you'd like to have them overclocked and making you up to 350% more in profits with ultra quiet fans too! PM me for details if interested.
Yes, the fans sound different for the first second after I start the batch file that calls cpuminer 20 times. It's like, the miners start at full power, then get the command to go low power mode immediately.
I'm using an ATX PSU. Don't think it has any problems. They all power fine. (Sure, it's not gold or platinum rated, but it still spits out 12 volts.)
I put a 200 ms delay after each "start" command in the batch file, and then I put a "taskkill" at the very start so it kills all the miners before starting. I no longer notice or hear the hum since putting in the delay between instances.
That way, I can switch pools and it takes 2 seconds. I can also now introduce a timer to restart the miners, say, once every 48 hours or something.
cpuminer has no api, and always reports zero hash, so there's no way to detect a bad unit except through the pool. I'll need to make something that just reads the output for "yays!" and if too much time has passed, then that particular instance is restarted.
As for modding the miners, I'm in the Philippines. It might become too expensive with shipping.
Can you share your scrypt or batch file ? I'd like to use it too....
There is no power down etc.command for the fans on the GC3355 miners... the fans are just ON at 12V, period...IF your fans are slowing down then speeding up, your psu is being overloaded...
thx