Copied from GPU-Z Homepage:


GPU-Z is a lightweight utility designed to give you all information about your video card and GPU.


Main Features


* Support NVIDIA and ATI cards

* Displays adapter, GPU and display information

* Displays overclock, default clocks and 3D clocks (if available)

* Validation of results

* No installation required

* Support for Windows 2000 / XP / Vista (both 32 and 64 bit versions are supported)

* BETA SOFTWARE - please test and post feedback in the forums

* .. and yes, the author of CPU-Z has granted us permission to use a name similar to his product. Thanks Franck.


Documentation

It's so simple to use, you don't need documentation.
Just download and run the binary. 



Changelog:


* Clock reading on ATI cards fixed

* GT200b is now detected as 55 nm

* Added detection for GeForce GT 120, GT 130, GT 130M, FX 5200, 9400 GT, 9600 GSO 512, FX 2700M, 9500 GS, Quadro FX 540M, Quadro FX 3700M, 9650M GT, Quadro FX 370M, 9400 IGP, 9300 IGP, 8200M G

* Added support for S3 Chrome 500 Series

* Added new ATI logo

* Fixed screen corruption during screenshot of sensors tab

* Added support to show lowest, highest and average reading on sensors tab
(click on sensor value to switch)

* Fixed number of texture units on RV730

* Fixed Catalyst version reading