I’ve been using the following pattern in order to unthrottle the GPU for raw performance measurements:

QSurfaceFormat format = QSurfaceFormat::defaultFormat();

format.setSwapInterval(0);

QSurfaceFormat::setDefaultFormat(format);

However, it is not working with QNX 7.0.4 on the i.MX8QM. It seems that this is due to the code at:

https://code.woboq.org/qt5/qtbase/src/plugins/platforms/qnx/qqnxwindow.cpp.html#760

which hard codes SCREEN_PROPERTY_SWAP_INTERVAL to 1. It would be nice to have this addressed for benchmarking.