have you tried 8gb ram for the mobo's? I use minimum of 8gb for all my rigs, which all mostly run dual channel ddr3 8gb, I think I have 1 rig that is doing single channel but that's because I goofed. I don't see any of the silly problems majority of noobs seem to experience, only thing ive had to experience so far is not enough power for the gpus and that's it
maybe try an ssd instead of a pendrive too, those were never made for what you are trying to use it for
Thanks. I actually have a couple extra sticks around here. I will try it an report back.