[Interest] Optimizing performance with hundreds of widgets

[Guenter Schwann]

On Mittwoch, 15. Februar 2017 17:28:22 CET Gibbs, Matt wrote:
> Hi All,
> 
> I’m working on a Qt-based project to display rapidly updating information
> from a control system.  I want to display hundreds of signals, each
> updating at about 10 Hz.  As a performance test, I’ve thrown 500 Labels in
> a grid layout, and fire a timer every 100 ms which calls setText on each
> label.  This ends up being surprisingly CPU-intensive: on reasonably modern
> hardware (2012 MacBook Pro), I use 70% of one CPU.  This doesn’t leave me
> much overhead to do anything else.

I get about 25% CPU usage on my 2.5GHz Linux Notebook.
And when I use a single custom widget to draw all texts in a single 
paintEvent, CPU usage drops to about 15%.

https://gitlab.com/gschwann/WidgetsPerformance 

-- 
Günter Schwann | Freelancing Software Engineer | Qt Expert
Partner Consultant of Viking Software
guenter at vikingsoft.eu