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
This motherboard will support up to three graphics cards and is optimized for dual card operation.
For best video performance you will want to populate the top most PCI Express slot with your video card and try to avoid using the secondary slot. The secondary slot is hardwired for 8x PCI Express lanes and borrows from slot 2 (the primary).
Boards like this are really quite fun to mess with and even though the last slot is hardwired to 4x lanes you can still run a third card either as a dedicated PhysX processor or play around with 3-way Crossfire. Sadly, both of those options are a little outdated leaving you with the best option of using a discrete sound card since we all want better audio in our lives.