ATI Radeon HD 3870 X2 Dual GPU 1GB DDR3 PCI Express (PCIe) Dual DVI Video Card ATI Radeon HD 3870 X2 1GB GDDR3 PCI Express Dual DVI Video Card General Features: Two (2) ATI Radeon HD 3870 GPUs 320 stream processors per GPU 825 MHz core clock 1 GB GDDR3 memory 256-bit memory interface 900 MHz memory clock PCI Express 2.0 x16 interface Supports Microsoft DirectX 10.1 with Shader Model 4.1 Supports OpenGL 3.2 Dynamic Geometry Acceleration