SAPPHIRE HD 4870 X2 2G GDDR5 PCI-E Specifications I/O Output: Dual DL-DVI-I+HDTV Core Clock: 750 MHz and Memory Clock: 900 MHz, 3.6Gbps Stream Processors: 2 x 800 PCI Express 2.0 x16 bus interface 2x 1024MB /2x256bit 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