z77 slot32GB. Expansion Slots. PCI Slots, 1 xPCI Express 3.0 *2.0 x16 slot (x16 mode) 1 xPCI Express 2.0 x16 slot (maximum x4 mode, compatible withOn-Board SATA • SATAIII controller integrated in Intel® Z77 chipset - Up to 6Gbs transfer speed.