from gigabyte website.you do not have onboard graphix,the only way to crossfire is with 2-graphics cards.
Switchable Graphics with LucidLogix Virtu GPU Virtualization
GIGABYTE Z68 motherboards are enabled with LucidLogix Virtu GPU Virtualization technology which allows users to dynamically switch between their built-in graphics and their high-end, 3D discrete graphics cards. This is ideal for gamers who require high-resolution gaming and still want to enjoy the built-in media features of 2nd generation Intel® Core™ processors. In so doing, switchable graphics helps to dramatically reduce PC graphics power consumption.
Multi-display support with CrossFireX and SLI™
Flexible graphics capabilities supported for either CrossFireX™ or SLI™ action, delivering the ultimate in graphics performance for gaming enthusiasts who demand the highest frame rates without compromising on resolution.
AMD Phenom II 1100t @4.0Ghz /Asus sabertooth 990fx/2-sapphire 2G 6950 dirt 3 edition cards(shaders unlocked,880/1375)/160G intel ssd/16G G-Skill Ripjaw 1600/2-samsung 24" monitors 1920X1200/Corsair AX1200W psu/W7 pro 64,G19/G7 keyboard&mouse,Cooler master HAF932,corsair H100 water cooler,Zalman ram cooler.