https://www.techpowerup.com/226385/a...expansion-slot

ASRock unveiled the Z170M-PIO2, a micro-ATX socket LGA1151 motherboard with a unique angled PCI-Express gen 3.0 x16 slot that lets you install a graphics card parallel to the plane of the motherboard. It takes away the need for PCIe riser cables in certain PIO form-factor compliant SFF chassis. The PIO form-factor is an emerging standard of compact SFF cases that you mount along the VESA wall-mount bolts of your display. Technically, the board conforms to the uDTX form-factor, but is compatible with micro-ATX and PIO form-factors.

Its star-attraction aside, the Z170-PIO2, as its name suggests, is based on the overclocking-ready Z170 Express chipset. It supports up to 32 GB of dual-channel DDR4 memory with its two memory slots. The board draws power from a combination of 24-pin ATX and 4-pin CPU power connectors. Besides the angled PCIe x16, you get an mPCIe slot (for WLAN cards), and one 32 Gb/s M.2 slot. Four SATA 6 Gb/s ports, 6-channel HD audio, four USB 3.0 ports, and gigabit Ethernet make for the rest of its connectivity.