Qt data visualization zoom performance

[Tom asso]

My C++ widgets application (no QML) displays data as a Q3DSurface, with 1450 rows and 1113 columns. When I zoom with the center mouse wheel the zoom is not very smooth, with visually noticeable jerks. My application invokes Q3DInputHandler::wheelEvent(event) without any "custom" processing by me. In my application main() I try to optimize graphics performance as follows:

Q3DSurface *graph = new Q3DSurface();
// Improve zoom performance?
graph->setOptimizationHints((QAbstract3DGraph::OptimizationHint::OptimizationStatic));

But I still do not see any noticeable difference in zoom performance.
Is there some other way to improve zoom performance? A non-Qt 'C' application which calls OpenGL functions directly, displays the same data as a 3D surface on my laptop with very smooth zooming; so I don't think the jerky zoom is due to hardware limitations but rather to overhead in the Qt/Q3DSurface code. My laptop cpu is a dual-core Intel i5-7200U CPU @ 2.50GHz with an Intel 5916 graphics card.

Thanks
Tom