That means the PCIe 1x slot has a 4GB/s bandwidth, 4x has 16GB/s available, 8x is 32GB/s, and 16x utilizes 64GB/s for today's graphics cards. It makes the most sense to look at the two highest-end ...

A couple of boards look like they have support but I remember something about getting a board that supported SLI support will not have a PCIe slot ... user setup in a 8x slot that appears to ...

With options for 1x, 2x, 4x, 8x, and 16x slots, that increases the maximum potential bandwidth for a PCIe 4 slot to 64GBps. This gives anything that plugs into a PCIe slot more headroom ...