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 :-)
The troubleshooter in me says to take out the middle two cards (middle PCIe slots) and see how many cards you see. If it's 4, it may just have to do with the number of cards being seen by the system. Maybe the BIOS runs out of memory trying to address that many cards. Make sure all the features you don't need are turned off in BIOS... all the fun stuff