The ASRock Z77 Extreme11 comes with three PCI Express 3.0/2.0 x16 slots, one PCI Express 2.0 x16 slot (working at x4), and three PCI Express 2.0 x1 slots.
Usually, on motherboards based on the Z77 chipset, there are only two PCI Express 3.0 x16 slots, as these slots are controlled by the CPU, not by the chipset. On this motherboard, however, there are three PCI Express 3.0 x16 slots. This is accomplished by the presence of a PLX 8747 switch chip. This chip also allows the first PCI Express 3.0 x16 slot to work at x16 speed when two video cards are installed; usually, when two video cards are installed, the first slot drops its speed to x8. When three video cards are installed, the first slot works at x8. See the table below. Since these slots are controlled by the CPU, they will offer PCI Express 2.0 bandwidth (8 GB/s at x16) when a “Sandy Bridge” CPU is installed, but PCI Express 3.0 bandwidth (16 GB/s at x16) when an “Ivy Bridge” CPU is used.
The fourth PCI Express x16 slot (PCIE7) is controlled by the chipset, always works at x4 speed, and uses 2.0 bandwidth. You will need a computer case with at least eight expansion slots if you want to install a dual-slot video card in this slot. (Computer cases usually have seven expansion slots.)
The PCI Express x16 slots support both SLI and CrossFireX technologies.
The ASRock Extreme11 also has a Mini PCI Express slot, which comes with a dual-band Wi-Fi IEEE 802.11a/b/g/n card with Bluetooth 4.0 capability.
In order to properly accommodate the additional PCI Express devices that are on this motherboard (the additional SATA/SAS and USB 3.0 ports), the board makes use of a PLX PEX8608 switch chip. This chip automatically switches the available PCI Express lanes to the devices that need them. On motherboards with too many PCI Express devices without a switch chip, you need to manually disable devices on the motherboard setup in order to achieve full performance on devices connected to the USB 3.0 and SATA-600 ports when transferring files at the same time.