OpenGL on multi-monitor systems

While every multi-monitor system supports software OpenGL, support for hardware-accelerated OpenGL depends on the operating system and the display drivers.
Why is hardware acceleration important? OpenGL applications will run much faster, and some applications won't work without it, for example games such as Quake 3.

Windows 98 and Windows Me

To get hardware acceleration, you need to disable all secondary monitors. You can do this from display properties, or more convenient with UltraMon™. If you want to use your secondary monitor(s) while working with an OpenGL app on the primary, re-enable secondary monitors after the OpenGL app has started. You will not be able to move the OpenGL app to a secondary monitor, or start another hardware-accelerated OpenGL app, but you can use the secondary monitors for any standard 2D apps.

Windows 2000/XP and later

Everything described above for Win98/Me will also work on Windows 2000/XP and later operating systems. But depending on the display drivers of your video cards, you may not have to disable any monitors. Here's a list of chipsets/display drivers that have at least some support for multimon OpenGL:

Chipset/driver	Notes
3Dlabs Permedia 3, Oxygen VX/GVX, Wildcat	GVX and Wildcat cards have multimon OpenGL, even across multiple cards or heads (in the case of dualhead GVX and Wildcat cards). Limitations: all monitors need to use the same display resolution. VX1 and Permedia3 don't have multimon OpenGL with current drivers, but did with earlier ones
ATI Fire GL3, RADEON, RAGE 128, RAGE MOBILITY	accelerated OpenGL without disabling secondary monitors
Matrox G450	accelerated OpenGL on the primary head without disabling secondary monitors
Nvidia (Detonator 40 or later)	acceleration on all monitors, disabling secondary monitors isn't necessary. Acceleration is also supported across multiple Nvidia cards. Windows can be moved between monitors, and also stretched across multiple monitors. Please note that not all applications will work when stretched across multiple monitors, especially games like Quake3 and UT2003 might crash after a short while. Nvidia drivers are available here: Nvidia, 3DChipset
SGI Visual Workstations

Here's an interesting configuration with a 3Dlabs and an Nvidia card: 'I wanted to let you know that I have a PCI TNT2 as my primary with the 3.78 drivers and either an AGP VX1 or a PCI GVX1 as the second using the 2.15-0280 drivers from 3DLabs. This works great. I have had some other combinations but to get two screens with windowed OpenGL hardware acceleration the TNT2 had to be the primary and the 3DLabs card had to be the secondary'.