SAPPHIRE HD 4870 512MB GDDR5 PCI-E Specifications Display Output: Dual DL-DVI-I+HDTV Core Clock: 750 MHz Memory Clock: 900 MHz, 3.6Gbps PCI Express 2.0 x16 bus interface 512MB /256bit GDDR5 memory interface Dual Slot Active Cooler HDMI compliant via dongle 7.1 Audio Channel Support Microsoft® DirectX® 10.1 support Shader Model 4.1 support