I'm looking to buy a new graphics card for my PC to replace my weedy GeForce GT 630 one. I understand that my motherboard requires a PCI-e x16 slot for modern cards, so I looked inside my desktop first. My PC uses a MSI B75MA-P45 motherboard with three PCI slots, labelled "PCI_E1" (currently used), "PCI_E2" and "PCI1". See the picture below. Since none of these are labelled PCI-e x16, I thought I might need to buy a new motherboard first. But when I looked up the specs on my motherboard, every site says that it already has a PCI-e 3.0 x16 slot! This makes no sense to me because none of the slots are labelled as such, and PCI-e x1 (which I assume is the label for the first slot) is very different from PCI-e x16. So if I buy, for example, a GeForce GTX 970 card, will it actually be compatible with my motherboard?