Typically, graphics cards use PCI Express x16 slots. That's a PCIe slot configured ... many GPUs in the past have used x8 or even x4 connections. This limits the bandwidth available between ...

If you ever looked at a PCI to PCIe x16 adapter and wondered what’d happen ... the same card was run in a PCIe x4 slot, as well as in an x1 configuration, both with noticeably higher performance ...