The ASRock X79 Fatal1ty Champion comes with five PCI Express 3.0 x16 slots and two PCI Express 2.0 x1 slots. Socket LGA2011 processors have a total of 40 PCI Express 3.0 lanes for video cards. This allows a very high-end configuration for the PCI Express x16 slots, but the exact configuration used will depend on the motherboard model.
The PCI Express x16 slots are labeled PCIE1, PCIE3, PCIE4, PCIE5, and PCIE7. The ASRock X79 Fatal1ty Champion allows the configurations listed in the table below.
Even though the motherboard has five PCI Express x16 slots, you can “only” install up to four video cards. As you can see from the table, if only two video cards are installed, install them in the first and in the fourth (PCIE5) slots for the best performance.
When installing dual-slot video cards, you “kill” the slot immediately to the left (looking at the motherboard with its rear connectors facing up) of the slot being used. Basically, this means that when using the second (PCIE3) PCI Express x16 slot, you “kill” the third (PCIE4) slot, as described in the above table.
If a fourth dual-slot video is installed (in the fifth, i.e., PCIE7 slot), you will need a case with at least eight expansion slots.
All PCI Express x16 slots support both SLI and CrossFireX technologies.
When more than one video card is installed, you must install an additional power connector to the motherboard, which is located near the fifth (PCIE7) PCI Express x16 slot.
In order to properly accommodate the additional PCI Express devices that are on this motherboard (the second Gigabit Ethernet port, the eight additional USB 3.0 ports, the four additional SATA-600 ports, etc.), the board makes use of a PLX PEX8605 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.