I have acquired a PNY nVidia M4000 (PCIe 3.0, 4 DP slots, 8GB, for four monitors, 120W) before I noticed (dummy me) that it was a PCIe 3.0 card, and I have a PCIe 2.0 mobo (ASUS M5A99X EVO - ver 1).
Additional specs: AMD FX-8350, 32GB RAM (4x8) Crucial Ballistic Elite DDR3-2133, Current GPU...