Wich is better?

[dark_reaper]

I am currently looking into a new video card or cards. I am just wandering wich is better.
A single 256mb videocard for example a GeForce 6600 or 6800 or dual 128 like the GeForce 6600?
I have just bought a new MB with 2 pci-e slots. just want to see wich is better.

[Nvidia]

If this helps you at all, a single PCI-E 6800GT outperforms two PCI-E 6600GTs. A very small margin, but it still beats it.