Really? It came with a note that says: The EVGA GeForce GTX 700 Series graphics is a cutting edge card that ships with the latest technology including a full UEFI BIOS.
I cam confirm this as a fact. The 750ti will be fine in a non-UEFI motherboard. I just finished upgrading a family member's rig that is very similar (AM3, non-UEFI mobo using Win10 and a GTX 750ti).