I can not help much with mother board questions but i run three screens at "1920"x"1200". I use two cards to feed three screens. The three screens are used as one desk top (some use all screens for the same data IE the same pic/info is on all screens).Two ,or more,matching cards are usefull as you may want to join them at some stage for more power. Ask if this has not helped and i will try to answer.
What is ransomware and how do I protect my PC from Petya?