In many situations, two graphics cards Radeon HD 4830 in Crossfire are quicker than an unique Radeon HD 4870. The price of one Radeon HD 4830 is around 150$ and the price of one Radeon HD 4870 is around 300$. So if you already have a Radeon HD 4830, buying a new one
makes it possible to set up a decent gaming system.
Call od Duty 4 – Direct3D Test
Quake Wars – OpenGL Test