I have a 750i and a 780i. My ASUS P5N-D (750i) smokes my 780i which is a premium board (supports 3-way Sli also), I can't speak for the 790i never owned one. The P5N-D has 2x PCI Express 2.0 x16, I run my E8500 at 4.001GHz with room to spare, HyperX 1066@1066 2.3v with no problems.