Do I Need An SLI Certified Motherboard to Use SLI?

I recently upgraded my computer and am just inquiry if I can upgrade to a dual video card configuration? My motherboard supports 2 X PCI-E 16X. So in turn could I use dual cards?

My Specs are as follows:

ASUS M4A79 Deluxe AM2+/AM2 AMD 790FX ATX AMD Motherboard

XFX PVT98WYDBF GeForce 9800 GTX+ Black Edition 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card

SILVERSTONE ELEMENT ST65EF 650W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS BRONZE Certified Active PFC Power Supply

OCZ Platinum Series 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel

AMD Phenom II X4 940 Deneb 3.0GHz Socket AM2+ 125W Quad-Core Black Edition Processor