Those "low cost processors" STILL eat power - and have very poor performance per watt vs. ASIC (where available).
They might be competative on a per-watt basis vs conventional CPUs, but there doesn't seem to be enough of a market to JUST add on a "CPU + RAM" to make the things viable - and you ARE going to need the RAM to be able to mine with them, at which point any potential cost savings drops to near nothing on a hash/$ and hash/watt basis vs existing multi-core server CPUs on existing motherboards.
It's going to get worse once AMD starts releasing "Zen" CPUs with 16+ cores per CPU package/chip late this year or early next year.
The idea is there would be a micro computer controller, these usually carry 2-4gb of ram, the idea is these would each increase the hashrate per stick. So say you have a $70 windows mini pc as the controller and a powered usb hub with the usb sticks. A row of asic sticks would hopefully allow you to be competitive on a $/Hashrate level. The idea isn't exactly for now it is for the future and zen, zen is nothing in the cpu world. It already is only rumored to compete with i5's not i7's, a 16 thread 8 core cpu isn't as impressive as it used to be.
ASIC USB sticks are a lot more efficient though - and none of THEM are profitable any more except the Moonlander and possibly the Gekko *IF* your electric is cheap enough.
