Diamond Viper 3870X2PE31G ATI Radeon HD 3870 X2 PCIE 1GB GDDR3 Dual GPU Engine Graphics Card PCI-Express x16 graphics card features two ATI Radeon 3870 GPUs for outstanding HD graphics performance 1024 MB of GDDR3 RAM running on a 256-bit interface at 900 MHz; graphics processor has core clock speed of 925 MHz Supports Crossfire X for easy upgradeability by adding a second graphics card Support for full DirectX 10.1 and Shader Model 4.1, and OpenGL 2.0 Backed by a 1-year warranty