Zotac GeForce GTX 660 AMP 2GB GDDR5 192-Bit PCI Express 3.0 DVI-I + DVI-D HDMI DP SLI-Ready Graphics Card ZT-60902-10M 960 processor cores, Engine clock (base):1046 MHz (boost) 1111 MHz, Memory clock: 6608 MHz DisplayPort 1.2 (4K ready), HDMI 1.4a (4K ready, w/audio), DVI-I (VGA with included adapter), DVI-D (digital only), Quad simultaneous display capable, HDCP compliant, Dual SLI bridge connector (2-way) NVIDIA GeForce driver, Microsoft DirectX 11, OpenGL 4.2, Microsoft Windows XP/Vista/7 x86/x64 ED 480p, HD 720p, HD 1080i, Full HD 1080p, Quad Full HD (4K)