XFX AMD Radeon HD 7770 - FX-777A-ZDF4 - Double D HD 7770 1000MHZ 1GB GDDR5 Display Port HDMI Dual DVI PCI-E Engine Clock: 1000 MHz Video Memory: 1GB DDR5 Memory Clock: 4.5 GHz Memory Interface: 128-bit Bus: PCI-Express 3.0 x16