My mac was behaving strangely after using Photos. I imported a couple of photos and created a slideshow. After a couple of hours playing with it, I noticed that my mac was using discret GPU even no application that requires dedicated GPU was running. Even on idle state my mac was running hot.
So, I checked what could have cause OSX to run on dedicated GPU even on idle state. I found out that com.apple.photos.ImageConversionService was running in the background and still using the discret GPU.
Below is the steps to forcibly stop it from running:
1. Open Terminal and type the following command
ps aux | grep com.apple.photos.ImageConversionService
You should see similar output.
johndoe 1925 0.0 0.0 2445076 824 s000 S+ 4:33AM 0:00.00 grep com.apple.ImageConversionService
Note that I only need the PID. In my case it's 1925. Yours could be different.
2. Now that I have identifed the PID, I can now force it to stop. In the terminal type the following command:
sudo pkill -9 1925
You will be asked with password and if everything goes well, OSX should have now switched to Intel Iris Pro.
If you're using Photos to import videos and toyed around with it? Chances are, you have ran into similar issues like this. Instead of finding com.apple.photos.ImageConversionService try finding com.apple.photos.VideoConversionService