Created attachment 173220 [details]
DisplayCAL internal display ICC, Datacolor SpyderX

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SUMMARY
At least on an Intel Gen9 graphics platform (i7-8650U with the UHD 620 iGPU), setting an ICC profile created by DisplayCAL will cause GPU usage to increase by a huge amount, especially when there is a video playing on the color-managed display. When moving a video between a display that has an applied ICC profile and one that does not, the difference in GPU usage and power consumption is immediately noticeable.

STEPS TO REPRODUCE
1. Start playing a video or do something else that causes constant screen content changes
2. Begin monitoring the system's GPU usage or power consumption
3. Go to the Display and Monitor configuration and load an ICC calibration profile for the display that the video is playing on 

OBSERVED RESULT
GPU usage increases substantially along with power consumption, intel_gpu_top shows that kwin_wayland is the process responsible
The Render/3D usage can reach as high as 80% on the testing system

EXPECTED RESULT
No noticeable change in GPU usage or power consumption, much like with Night Color

SOFTWARE/OS VERSIONS
Arch Linux, Plasma 6.1.4, QT 6.7.2, running Wayland 1.23.0, plasma-wayland-protocols 1.13.0, wayland-protocols 1.37

ADDITIONAL INFORMATION
Machine is a Dell Latitude 7390 2-in-1 with the i7-8650U, which is equipped with the Intel UHD 620 iGPU

Attached is the ICC profile which DisplayCAL generated for the internal display, although the same problem occurs when an external display is calibrated as well