The graphics rendering on my development machine "feels" slow so I've just bought a graphics card to replace the on board graphics card.
Before I install it I want to run some software that will measure the performance of my current card so that I can compare the before and after.
Can you recommend something that will give me an objective measure of performance change?
The latest 3DMark will stress your video card to its absolute limits. Run all the tests and save the statistics. When you put your new video card in, run it again and compare.
Don't be sad if neither card can do very well, though. It is an intense benchmark.
Looking at hardware review sites like Tom's Hardware (http://www.tomshardware.com/reviews/Components,1/Graphics-Cards,4/) and AnandTech (http://www.anandtech.com/video/) should give you a good idea of which applications and games stress graphic cards the most.
Right now 3DMark, Assassin's Creed, Call of Duty 4, Crysis, Enemy Territory: Quake Wars, World in Conflict and Oblivion seem to be good candidates.
The Video Card Stability Test is a nice and free little benchmark and load test for the GPU. Another very nice free benchmark is Lightsmark 2008.
For DirectX performance, the 3DMark versions work the best. For OpenGL performance, I like Unigine Heaven. You can download them all at Test My Geek Stuff.