EVGA GeForce GT 640 4096MB GDDR3 Single Slot, Dual DVI and mHDMI Graphics Card 04G-P4-2647-KR Microsoft DirectX 12 API (feature level 11_0) Support GPU Clock: 901 MHz Shader Clock: 1803MHz Memory Clock: 1334 MHz CUDA Cores: 384 PCI-Express 3.0 4096MB GDDR3 128bit NVidia SMX Engine, NVidia Adaptive Vertical Sync, NVidia Surround, Support for Concurrent Displays, NVidia PhysX, NVidia 3D Vision Ready, NVidia CUDA Technology