Zotac GeForce GTX 770 2GB GDDR5 PCI Express 3.0 DVI HDMI DisplayPort SLI Ready Graphics Card ZT-70301-10P Memory 2GB DDR5 256 bit Engine Clock - Base Clock 1059 MHz (NV ref. 1046 MHz) - Boost Clock 1098 MHz (NV ref. 1085 MHz)Memory Clock: 7010 MHz (7.0Gbps) Two dual-link DVI (DVI-I + DVI-D) + HDMI + DisplayPort Open GL 4.3, Microsoft DirectX 11.1 API (feature level 11_0), Windows 8/7/Vista/XP (32 - or 64 bit)