GPU-Z

TechPowerUp GPU-Z (or just GPU-Z) is a lightweight utility designed to provide information about video cards and GPUs. The program displays the specifications of Graphics Processing Unit (often shortened to GPU) and its memory; also displays temperature, core frequency, memory frequency, GPU load and fan speeds.

Features
This program allows to view the following information of the video card:
 * Graphics Card's Name
 * Fake GPU detection
 * GPU Internal Codename
 * Technology Process
 * Chip Die Size
 * Number of Transistors
 * Support for DirectX / Pixel Shader
 * Memory Type
 * Amount of Video Memory
 * Memory bandwidth
 * Type of Bus
 * Width of the Bus
 * Frequency of the GPU (default / overclocked)
 * Memory Clock
 * Driver Version
 * BIOS Version
 * Sensors
 * GPU Core Clock
 * GPU Memory Clock
 * Low GPU
 * Fan Speed
 * Nvidia SLI/AMD CrossFire