Hi all,
This is somewhat of a public service announcement.
I've spent the last several days troubleshooting an issue, and the solution wasn't what I had expected. I have two machines, each running the exact same version of my software. The first machine is a 4090-equipped laptop, the second is a brand-new workstation with an RTX 5000 Ada Generation GPU.
One particular section of the software, which has always run really well on the laptop, was performing terribly on the new workstation (i.e. <1s replot time on the laptop, 30+s replot time on the workstation). I've spent days checking OpenGL drivers, switching to Direct3D12, etc., but nothing appeared to be incorrectly setup or configured on the workstation, and nothing fixed the poor performance on the workstation.
I've always used setOpenGl() on my plots, so didn't even think to try that, especially given the power of the new RTX GPU in the workstation. However, I've just commented out the setOpenGl() call on this one particular module, and now the new workstation is performing even better than the laptop.
I know the setOpenGl() function is still marked as experimental in the documentation, so I suspect there is something weird going on under the hood with the new RTX OpenGL drivers. OpenGL is correctly initialised (I check with QCustomPlot::openGl() after initialisation), so I suspect this is an RTX driver-side issue more than anything.
Hopefully this saves someone else from hours or days of troubleshooting!