I'm looking to build a small FFmpeg based video encoder using a BlackMagic Intensity Pro 4K capture card. This card requires a PCIe 4x slot. What's the smallest motherboard/case combination that will hold a 4x card?
There are lots of small barebones systems, but most have mini PCIe (1x) connectors, and all of the PCIe risers I've found are either 1x to 1x or 1x to 16x. The 16x connector is way too large.