Multi GPU Index
The Hardware Asylum Multi-GPU index is a portable set of data we can use to determine the multi-gpu potential of any motherboard. A higher index number indicates a favorable condition for multiple graphics cards while a lower number indicates a hindrance in one of our leading indicators. Since the Index is not dependent on system architecture it can be applied to any motherboard regardless of processor or chipset generations.
Max Support: 4x
Max Supported: 3x
As indicated by the PCI Express layout chart there are a total of five 16x PCI Express slots on this motherboard with all five using bandwidth earmarked for video cards. The configuration is rather unique because you are given a choice of bandwidth allocations depending on your system configuration.
The five 16x slots all use bandwidth directly from the CPU. This configuration changes if you are using a 28-Lane processor where slot #7 only get 4x lanes of bandwidth. Slots #3 and #4 share 8x lanes each which are borrowed from slot #1. If slot #3 is populated then #4 is disabled completely.
For best video performance you will want to populate slots #1 and #5 with video cards. For proper triple card configurations you'll populate slots #1, #3 and #5. Slot #7 is really an extra slot on the X99A Godlike much like slot #4 so unless you have a 40-lane processor you will want to avoid using them.