Comment 17 for bug 981210

I get different result (in terms of whether QImage or QPixmap is faster) each time I run the program but I haven't shut down all other programs while running this test yet.

It would be good to calculate the max and the variance in addition the mean and min. We should know how noisy the measurement is.

Also, even though the QGLWidgets are not drawing concurrently I wonder if we should just have 1 widget and run the program twice (once with QImage and once with QPixmap).