QGLWidget and multiple windows

[ToddAtWSU]

I am running my program on Solaris 9 with 4 monitors and 4 graphics cards. Each monitor contains one plot window. Each plot window has a QGLWidget that holds a plot. To draw the plot I make many calls to glBitmap( ) and to print the image I make the call glReadPixels( ). I have noticed that once I open an auxiliary window and make one of these calls, my OpenGL draws occur very slowly. Is there a reason why I would notice a huge performance hit with opening one of these additional windows? What used to take 2-3 seconds to render now takes 30+ seconds to render after opening a secondary window. I don't know if this is an OpenGL issue or a Qt issue because everything seems to work fine until I open a secondary window over the plot window. Thanks again for your help!

[wysota]

Try moving your GL code to a separate binary so that you get rid of Qt dependencies (you can use GLUT to help you) and see if the problem persists. This should let you identify if the problem is with Qt or not.