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: 3x
As indicated by the PCI Express layout chart there are a total of three 16x PCI Express slots on this motherboard each using bandwidth earmarked for video cards. Slot two will be the primary video card slot and will run at a full 16x when only a single card is installed.
For best video performance you will want to populate slots two and five with video cards. Slot seven shares bandwidth with slot five allowing you to run three 16x based expansion cards on this motherboard but not in SLI. Sadly since the bandwidth is halved that does remove the option of running SLI + PhysX.
One notable feature of the EVGA Z390 Dark is that slot six, the dedicated 4x expansion slot is notched allowing you to install longer cards into this slot. You’ll be limited to 4x lanes of PCI Express but no longer limited to just 4x cards.