How do USB to VGA/DVI adapters work?
Those are external USB video cards. It’s a video card that is connected to your computer via low-bandwidth USB (480 megabits/sec), rather than high-bandwidth PCIExpress 16x slots (6400 megabits/sec) that is used for normal graphics cards. The low-bandwidth USB connection is why USB video cards are slow, unstable, limited in resolution, and have absolutely no 3D game graphics processing capabilities whatsoever. Though if all you want to do is view your email or low-definition streaming videos with it, it might be good enough for that. If you have a desktop computer with a PCIExpress 16x slot, a graphics card that supports 3 monitors natively like the ATI HD5000-series would be a FAR better solution– It will work much more seamlessly.
