HighPoint Rocket 1608A 8-Slot Gen 5

It's a slot of x16 size but electrically x4 This

Sometimes, a PCIe slot operates with fewer data lanes than the mechanical slot-type indicates Notice 'SLOT 13' are PCIe x16 slots but only Slot 3 has an x8

pciex16 slot * The PCIEX16 slot can only support a graphics card or an NVMe SSD If only one graphics card is to be installed, be sure to install it in the PCIEX16 slot

free penny slot * The PCIEX16 slot can only support a graphics card or an NVMe SSD If only one graphics card is to be installed, be sure to install it in the PCIEX16 slot