R740XD GPU Power Extension Card and PSU 2 GPU Nvidia A16

Dear All,

I want to install two GPU Nvidia A16 to a PowerEdge R740xd, I have the raisers but when I connect both GPU at raiser 2 & 3 the system only recognized one, is there any power extension card to plug one GPU in raiser 1 and the other in raiser 2? The system has two PSU 750w, is this enough or I need 2x1100w minimum? Thank you so much for support.