I am developing OpenGL Applications under Windows environment. When I run the applications I have faced one problem; when I change the Desktop display settings to 16-bit color mode my applications runs very fast, whereas in 24-bit color mode runs very slow. How to solve this problem? How to run my applications very fast in even 24-bit color mode?
What kind of video card/operating system do you have?
Did you try different pixel formats? Maybe you are not getting an accelerated context.
Somthing like 32-bit color, 24-depth, 8-stencil. This should work with anything made after the TNT2 or so.
-Won
usually if your application is fill limited, switching from 32 bit to 16 bit doubles the framerate. (guess why… 
)
when you want to make your app in 16bit mode as fast as with 32bit, you have to save fillrate.(blending/multipass consumes most of it. try to optimize them.). if you don’t have any room for fillrate optimizations, only new hardware can solve your problem.
If the Desktop settings color mode is 16-bit; it shows,
Vendor : Intel
Renderer : Intel810/810E
If the Desktop settings color mode is 24-bit; it shows,
Vendor : Microsoft Corporation
Renderer : GDI Generic
I am working on Windows 2000 Operating System.