Nvidia GeForce GTX 550 Ti, 1GB GDDR5, PCI-E 2.0 x 16, Graphics Card 192-bit Memory Interface Width192 CUDA Cores900MHz Graphics Clock 2050(MHz) Memory Clock NVIDIA SLI-ready: 2-Way, PureVideo Technology -HD, PhysX Technology, Microsoft DirectX -11OpenGL -4.1Bus Support -PCI-E 2.0 x 16, Windows 7 Maximum Digital Resolution -2560x1600, Maximum VGA Resolution -2048x1536, Standard Display Connectors -Mini HDMI/Two Dual Link DVI, Multi Monitor, HDCP, HDMI Audio Input for HDMI Internal Minimum Recommended System Power -400 W, Supplementary Power Connectors -One 6-pin