Graphics card not compatible with MoBo?

So this is by no means something that bothers me anymore but I just want to get to the bottom of it. Here what's the thing. I got Nvidia GT730 DDR5, cheap card long time ago for the old computer (I'm using it now). I installed it and even played through Black Flag for hours with no problem. But there was a thing. Whenever I start game or anything that ups the card's clock gets tiny small grain all over the monitor which you can't see from distance but is irritating at close. I RMAd the card and the same thing was present. Didn't matter to me few bucks so I put in the box and returned to the previous card. Now I decided to give this junk PC new power supply. Why? Because the requirements for card the were 300W 20Amps PSU and mine was 300W 14A (total crap). Got 450W Corsair with 32Amps rail and I just wanted better PSU in general. Surprise, surprise same thing happens.

I really don't care much now, I just want to know why is this happening. Motherboard is the only thing that comes to my mind.

Here is the board http://ift.tt/1F5Po6B



And the card http://ift.tt/107cf2C



So anyone can confirm because I'm not that savvy.

Graphics card not compatible with MoBo?