f your graphics card can deliver in 2D, it can probably deliver in 3D.
As far as performance goes, an easy way to test the performance loss is to install the iZ3D Driver, and play in Anaglyph mode. The loss should be similar to the loss with 3D Devices.
Please note, that while CrossfireX and SLI may output two streams, in most cases the game will only make use of One core in 3D mode.
For ATI Graphics Cards, we recommend a minimum of an ATI Radeon 4870.
For nVidia Graphics Cards, we recommend a minimum of an nVidia Geforce 8800.
http://www.iz3d.com/