2 GPU Slots on Mobo - can I use either?

The only thing the board can do is either block the pcie lane when a nvme drive is in use or bifurcate the nvme to x1 or x2 and reserve x1 for

One extremely common use of PCIe slots is upgrading or adding new local storage Mounting an SSD on your motherboard through a PCIe connection

which interview slot is best Yup, a dual slot graphics card will take up 2 expansion slots in your case, and hover over 2 PCIe slots if your particular motherboard has 2

which slot is best for gondola ride gulmarg Similarly, you can insert a PCIe x8 card into a PCIe x4 slot, but it'll only work with half the bandwidth compared to if it was in a PCIe x8