so what do you guys use since AB only supports upto 8 gpu? Tried looking for an answer but I can't seem to find any 
For AMD, Overdrive like it was already suggested, there is also an integrated tool in AMD driver's software, it supports my 2 GPUs just fine, not sure about 8 though. Another alternative could be GPU-Z.Problem is that it's a mixed and match rig (13 gpu total) so that's why I can't use afterburner. I tried the overdrive but it's quite confusing since I can't tweak it as I go.. didn't know GPU-Z can over/under clock GPUs
Anyway, I took the easy way out...shuffle my rigs around and now I can control those vega cards (although I do have another problem in another post)...
Thank you all for the help!