There are some performance issues with QPainter printing to some device (large plotter).
Paper size: A0
Resolution: 600 DPI
We set clip area with setClipRect() and than we set transformation which translates and rotates coordinate system according to ellipses major and minor axes. We draw some ellipses with above options and this is very slow because it creating temporary clipping region out of our initial rectangle and this clipping region made out of 27000 clipping sub-rectangles and it looks like they are created and destroyed for every single ellipse.
We are using QPainter::drawPath(), QPainterPath::arcMoveTo() and QPainterPath::arcTo() functions. It was working fast in Qt 4.7.4 environment.
Please see the attached printerperformancetest_v1.zip test program.
Noticeable for paper size A4 already, only in Native/PS format (-0). It is fast when using PDF (-p).