Backplane with eight PCIe x8 Gen4 slots and one PCIe x16 target slot. The OSS target backplane supports a PCIe Gen4 target cable adapter installed in the OSS target slot and up to eight PCIe x8 expansion cards installed in the expansion slots. Slots are backward compatible and support Gen1, Gen2, and Gen3 cards. OSS target backplanes only support OSS target adapters installed the target slot of the backplane. OSS PCIe backplanes support expansion cards designed to the PCIe PCI-SIG specification. This backplane operates with ATX power.