# Dual-monitor support
**URL:** https://discourse.glfw.org/t/dual-monitor-support/322
**Category:** support
**Created:** [January 14, 2005, 3:05am UTC](https://discourse.glfw.org/t/dual-monitor-support/322 "2005-01-14T03:05:17Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@system](https://discourse.glfw.org/u/system)
#### Post date: [January 14, 2005, 3:05am UTC](https://discourse.glfw.org/t/dual-monitor-support/322/1 "2005-01-14T03:05:17Z")
**nobody** wrote on [Friday, January 14, 2005](https://sourceforge.net/p/glfw/discussion/247562/thread/ba187c5b/#499a):
Hello,
If i understand, dual-monitor support will hopefully make it into version 2.6? I don’t know how long that will take, but for now, is the only solution to disable dual monitor support when testing in fullscreen?
Thanks, Stephen.
---
### Author:  [@system](https://discourse.glfw.org/u/system)
#### Post date: [January 14, 2005, 8:26pm UTC](https://discourse.glfw.org/t/dual-monitor-support/322/2 "2005-01-14T20:26:24Z")
**[marcus256](https://sourceforge.net/u/marcus256/)** wrote on [Friday, January 14, 2005](https://sourceforge.net/p/glfw/discussion/247562/thread/ba187c5b/#499a/2123):
I just tried a fullscreen GLFW app on a dual monitor configuration this week (ATI 9600 XP, DVI + VGA), and noticed that it used software rendering in fullscreen mode, but HW acceleration in windowed mode (even across two monitors at the same time). ☹
I don’t have access to more than one monitor at home, so I can’t do much development/testing atm, which is one of the key reasons for the lack of proper multimonitor support in GLFW. I think I got the basic concept for supporting/selecting multiple monitors through the Win32 API (that’s what I intend to add to GLFW in the future), but I don’t know what forces the fullscreen mode to SW rendering on my card (this is at my job).
I would be very happy if someone with the resources and the will to test/code/fix this could help out. I’m a bit stuck.
---
### Author:  [@system](https://discourse.glfw.org/u/system)
#### Post date: [January 14, 2005, 11:04pm UTC](https://discourse.glfw.org/t/dual-monitor-support/322/3 "2005-01-14T23:04:41Z")
**[slarew](https://sourceforge.net/u/slarew/)** wrote on [Friday, January 14, 2005](https://sourceforge.net/p/glfw/discussion/247562/thread/ba187c5b/#499a/9f35):
Hello Stephen again,
I have dual-monitors, how can I help? I have basic experience with the Win32 API. I am certain I can look into the appropriate function calls and such. Is there a place you could suggest I start? If you just would like me to test, I can do that too.
---
### Author:  [@system](https://discourse.glfw.org/u/system)
#### Post date: [January 16, 2005, 9:20pm UTC](https://discourse.glfw.org/t/dual-monitor-support/322/4 "2005-01-16T21:20:43Z")
**[marcus256](https://sourceforge.net/u/marcus256/)** wrote on [Sunday, January 16, 2005](https://sourceforge.net/p/glfw/discussion/247562/thread/ba187c5b/#499a/9f35/a620):
That would be more than great! I suppose you could start by testing how GLFW works on a dual monitor system under different situations. Then (if you can reproduce the problems I was seeing on an ATI 9600 under Win XP) you could perhaps take a look at:
lib\win32\win32\_window.c - \_glfwPlatformOpenWindow()
lib\win32\win32\_fullscreen.c (perhaps)
I suspect that the window opening code does something "wrong". There are a few differences in window flags for fullscreen mode and windowed mode, for instance.
---
### Author:  [@system](https://discourse.glfw.org/u/system)
#### Post date: [February 9, 2005, 3:14pm UTC](https://discourse.glfw.org/t/dual-monitor-support/322/5 "2005-02-09T15:14:08Z")
**nobody** wrote on [Wednesday, February 09, 2005](https://sourceforge.net/p/glfw/discussion/247562/thread/ba187c5b/#499a/7f92):
I have an application that is trying to create a fullscreen (not windowed) that is 2944x1200 in size (that represents two monitors – one 1920x1200 and one 1024x768). I configured windows XP to treat the two monitors as one (extend windows onto second display). What GLFW seems to do is squash everything onto just the 1920x1200 monitor. Is this a limitation or is there something I can do to get it to render to the full 2944x1200 size?