Who'd have thought that after more than a year of mining, I'd still be learning significant things about how it all works? Well, I suppose that's the attraction for me - pushing the limits of software and hardware and seeing what I can get a rig to do (or not do). Besides the standard temps and freqs... I bought a butt load of Compac USB stick miners with BM1384 chips on them (the same ones used on the S5) thinking I'd build a 49 stick rig and ride it to 500GH at 250W. Well, with that as a goal, I plopped all 49 of 'em into the hub, fired up a Pi and compiled cgminer-gekko from source and started working on it. What a challenge this is.
I've already learned the outer limits of cgminer's ability to run at full speed on a RPi. 22 sticks. Can the USB bus handle 5x that? Yes, of course. I can get them all to enumerate, but to get them mining at full speed on an RPi? Nope. Adding one stick at a time and monitoring progress from the console, while running nmon in another window, I saw the CPU usage climb with every stick I hotplugged... all the way up to 22, where the timeouts submitting shares slowed down enough for some of the sticks to where cgminer thinks they have failed and sets up a loop to re-initialize some of the newer sticks I plugged in - all the while drawing down the hashrate of every stick in the chain along the way in small fractions. There's no way I'm going to be able to get this rig running right on an overclocked RPi...
Next step, a core i7 desktop PC. Gotta get moar CPU power if this is gonna fly.
Mining is hard.