Why are imageres and fanartres so low?

I checked my advancedsettings.xml in the systemdir. I used to use on my previous Kodi installation on Shield an imageres and fanartres of 2160. Why is it so low for the Vero 4K+? Imageres is 540 and fanartres is 720…

There is a few reasons. One is that the Vero is not optimized, and therefore not recommended to be run at 4K for the GUI as it slows it down so saving them as such a large size is not necessary. Caching larger than the GUI is set slows down screen loading as it has to downsample each image and the larger images take longer to load and downsample. Additionally the downsampler that OSMC currently uses is not great and the more it has to shrink the images the worse the quality gets. There is several threads on this forum where this is discussed in more detail if you care to search for them. There is also the size the files take on disk which obviously can be quite substantial.

The fix is easy enough for anyone who wants to go their own way as it is just setting new numbers in a userdata advancedsettings.xml and deleting the thumbnails folder.

Thanks, clear answer. I understand that downscaling makes no sense, and tha 2160 is overkill. But 540 is on the low side when the GUI is at 1080; I can see that it is at low quality. I will set it to 1080 and see what the impact is on the speed. But I thought the advancedsettings of the system override the avancedsettings of the user?

I also saw that you can choose for an upscaler in the advancedsettings. Which one is recommended? Lanczos?

Maybe not as low as you may be thinking. That 540 is for posters and most skins do not show the poster filling up the entire screen. That particular number was chosen as it gives the best results in the OSMC skin. The magic number will likely be different depending on the skin. I personally use Estuary and have my imageres set to 720 and fanart to 1080. I have tested it on the OSMC skin and my settings do give a lesser quality there.

You have that backwards. Any options that are present on the system side are overridden if present in userdata.

The issue isn’t which method is being deployed for the downscaling. The limited testing I did with that setting in the past didn’t seem to change much. As I understand it the issue is lower level (hardware acceleration?) and not user changeable.

The default scaling Kodi offers in software is not great at all - be it up or down scaling. Kodi supports hardware scaling through OpenGL only which our devices aren’t capable of, they only support OpenGLES.