Would SLI speed-up Xinerama?

[Sascha]

Hello List!

I currently use a triple-head setup with 2 nvidia-cards:

- onboard nvidia 7xxx 
- pci-e nvidia 7xxx dual-head
- Athlon X2 2.7GHz
- 3 Screens at 1200x1600 (rotated. the rotation does not decrease the
performance significantly)
- Ubuntu Karmic, NVIDIA driver

The performance (just 2D desktop performance, no 3D or compiz) is ok,
but every time i use my Laptops (which are single-screen naturally) i
wish my Desktop performance were that great.
The Xinerama setup is just not that snappy.
There is a small lag with everything. Menu's appearing, Moving Windows,
general responsiveness.

Would a SLI System (SLI board + 2 SLI cards i guess) improve this
situation?

Thanks for any replies,
Sascha