nvidia cards + 4 monitors + 3d?

[port23user]

Here is the info on my video cards:
MSI NX7300LE PCI-e video card (Nvidia 7300LE)
Chaintech FX5200 PCI video card (Nvidia FX 5200)

Right now I have four monitors connected, two to each video card. It is set up with Xinerama and it kind of does what I need it to (eg, drag windows across all four monitors). However, I have two problems with this: 1. everything is slow (speed was fine when I had them set up with TwinView--only problem with TwinView was that I couldn't drag across monitors) and 2. I can't do 3d stuff (games, screensavers, etc).

From looking at http://www.nvnews.net/vbulletin/showthread.php?t=69211 it looks like there is a way to do a hybrid of Xinerama and TwinView. I don't really care how it's set up, just that it's semi-fast, it can do 3d, and I can drag across all four monitors. What do I need to do? Attached is my xorg config file. Thanks!!