Still doesn't explain why the first 4 cards are legit, the 5th is half ass, and the 6th is non existent. They are all recognized, powered on, and spinning. I'm writing something to see if I can send some work to the 6th card via cuda.
yeah, the RF engineer in me is clueless about that. :-)
oh wait... idea: the 5th and 6ths PCIe slots are farthest away from the northbridge/CPU though. Now add the USB cable length...
I studied communications engineering, but I mainly focus on protocols, software stacks, simulation of radio systems. My HF/RF knowledge is pretty rusty :-)