Details
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Bug
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Resolution: Cannot Reproduce
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P2: Important
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None
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5.15.1, 6.1
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Linux: Ubuntu 10.04.2 LTS on Virtualbox VM, AMD Ryzen 5 2600, 8 GB RAM, GL_VERSION - 3.1 Mesa 20.2.6
Qt 6.1
macOS: Big Sur on Macbook Pro (13-inch 2019) Intel Core i5 1.4GHz 8GB RAM
Qt 5.15.1 <- here I tested on different Qt version, but there should not be any difference compared to 6.1
Windows: Windows 10, AMD Ryzen 5 2600, 16 GB RAM, NVIDIA GeForce GTX 970, GL_VERSION - 4.6.0 NVIDIA 456.71
Qt 6.1
Linux: Ubuntu 10.04.2 LTS on Virtualbox VM, AMD Ryzen 5 2600, 8 GB RAM, GL_VERSION - 3.1 Mesa 20.2.6 Qt 6.1 macOS: Big Sur on Macbook Pro (13-inch 2019) Intel Core i5 1.4GHz 8GB RAM Qt 5.15.1 <- here I tested on different Qt version, but there should not be any difference compared to 6.1 Windows: Windows 10, AMD Ryzen 5 2600, 16 GB RAM, NVIDIA GeForce GTX 970, GL_VERSION - 4.6.0 NVIDIA 456.71 Qt 6.1
Description
I noticed a significant difference in graphics drawing performance on Windows compared to Linux and macOS.
Attached is a simple app with custom QGraphicsObject. Object paints a lot of ellipses and lines which is unusual of course. Adding simple QElapsedTimers showed a striking difference in time spent by QPainter in drawing.
Results of drawing 13000 points & lines:
Linux:
Drawing lines: 2ms
Drawing points: 3ms
macOS:
Drawing lines: 1ms
Drawing points: 4-5ms
Windows:
Drawing lines: 35ms
Drawing points: 38ms
If a view is static it doesn't make any problems, but if there is more stuff to draw or it's often repainted (for example while resizing) it makes apps a bit unresponsive.
Is it a known issue? Is there any chance for improvement? Maybe that's related to underlying graphics driver.