The last motherboard for AMD platforms that supports SLI is based on the Nvidia 980a chipset. There are few motherboards on the market with the 980a chipset that support the AM3 socket, and they are already becoming outdated due to the lack of SATA 6Gbps and USB 3.0 support. The ASUS Crosshair IV Extreme is the only one that combines these new features and CrossFireX and SLI support via the third party chipset.
You do software updates to get the most from favourite programs right? Updating a motherboard BIOS can in a timely manner is also critical. The guide to Flashing a Motherboard BIOS spells out the often complicated steps in plain english. PCSTATS Tips