EVGA GeForce GTX 680 Signature 2GB GDDR5 256bit DualLink DVI HDMI DisplayPort SLI Ready Graphics Card 02G-P4-2681-KR Base Clock: 1006 MHz Boost Clock: 1058 MHz Memory Clock: 6008 MHz Effective CUDA Cores: 1536 2048MB GDDR5 256bit Memory NVidia SMX Engine, NVidia GPU Boost, NVidia Adaptive Vertical Sync, NVidia Surround, Support for Concurrent Displays, NVidia PhysX, NVidia 3D Vision Ready, NVidia SLI Ready, NVidia CUDA Technology PCI express 3.0 Microsoft DirectX 11.1 API with Direct compute 5.0 Support, OpenGL 4.2 Support, OpenCL support