I run multiple external monitors on my now-elderly G4 PowerBook when it’s set up at my home office. It supports one external right out of the box, the second is handled with a CardBus (PCMCIA) card.
I’m upgrading; new MacBook Pro doesn’t have CardBus (adapters for ExpressCard/34 apparently don’t work), tried and hate the Matrox DualHead2Go, and I have investigated and then rejected USB video (too slow).
it looks like the best solution for multiple external screens on the new computer is a Magma breakout box with a PCIe display card. Magma says their customers have reported good luck with Nvidia cards.
The last time I had a desktop computer and bought a video display card to attach a monitor, the box was a PowerMac 7100 and the card was a NuBus card. I know nothing of such things in the modern world. I wish to drive a ViewSonic VM2030 at a resolution of 1680 x 1050 at full (32 bit) color. I don’t play games; I might watch DVD movies on this screen (although I could watch on the other external, an identical monitor which will be plugged into the built-in Thunderbolt video port).
Any particular Nvidia card I ought to get, or warnings I ought to heed about their adequacy for my needs, etc?