Weird fullscreen/windowed speeds

This is kind of a weird problem: a program I’m working on (a very simple heightfield renderer) runs noticeably faster in ANY windowed mode (even maximized at 1280x960!) than it does in fullscreen 640x480x32. The program uses the basic framework from the NeHe tutorials.

Details: My desktop and the program both are set to 32-bit color. The initialization code is the same as the Nehe code. The program renders a series of triangles (the heightfield) and then the vertex normals (with GL_LINES).

Does anyone have any ideas why the speeds might be different? I should add that the fullscreen mode still seems too fast for me to think it’s defaulting to software rendering or something.

[This message has been edited by lancekt (edited 03-24-2001).]

I am not confident, but maybe your card does not accelerate OpenGL in 32 bit color? Also such thing is possible: randomly under DEBUGGER software rendering launches without any reason (or there is a reason, but I dont know it).

I should mention I have a GeForce–it most definitely accelerates OpenGL in 32-bit color. (Just ran Serious Sam Test2 in 1024x768x32 a few days ago. )

I just noticed setting the VC++ settings to “Win32 Release” instead of Debug makes the speed seem more consistent (faster in fullscreen, slower in windowed). So it’s something with the debug compiler settings, I guess…still, weird.

I’m pretty sure it’s not using the software renderer in fullscreen debug mode…still seems too fast for that. Could be wrong, though. Anyone know a way to find out for certain?

[This message has been edited by lancekt (edited 03-25-2001).]

Even weirder…upgrading to Detonator 3 makes it FLY…

Excuse me - I wrote some wrong information. Under Borland Delphi/C++ Builder debugger (I dont know about MS Visual Studio, but maybe trouble is the same) on Riva 128ZX card it is sometimes (really randomly) very SLOW OpenGL. Although it still remains faster than software renderer, so I think it is slow hardware(:-)). Is there a way to determine which one I’m using at runtime?