Hello!

There is a problem when I skip through pictures - sorted by time - which have the same timestamp.
It seems to have a problem to bring them in a correct order.
If there are many files with equal timestamp, i often get into a continuous loop (files are repeating / chaotic).

Is it a known issue?

In which mode are you experiencing this skipping? Full screen, or normal viewing (just using the Previous/Next buttons)?

This is a known problem since 2012.

https://forum.kde.org/viewtopic.php?f=213&t=102640

What it looks like is that when you mass download from a site with a high speed connect the time stamps can be fractions of seconds inbetween downloads. Gwenview appears only to sort day, hour, minute (and possibly seconds). When you order by date it is not using the full time stamp but only most of it. Then when you start viewing the pictures, due to the pictures having the same day date and minute gwenview likes to sort everytime you view one. This causes the flipping around of positions of the pictures.

There is one work around that usually works, but it comes with a warning. If you use this method it can take an absurdly long time to sort. I tried it by dumping 8k texture images from all my 3d texture directories into one big directory.

Basically, load the directory you want, wait till the thumbnails are done, then highlight the very last one, and press "shift-home" to highlight them all. Then with 8k pictures you can wait somewhere around 20+mins till they are properly sorted.

I find this time to sort it out extremely absurd. If you can sort 8k image files in maybe 20 seconds tops, it shouldn't take more than 2 minutes to get it completely sorted, assuming you use a sane method of sorting. This seriously needs to be looked at and fixed.

I think the primary problem with this is that the sort is hitting a single core only, and sorts absolutely everything rather than dividing the list by date.

Could it be sped up by sorting into "by date" blocks (11/01/2010 = 1, 11/02/2010 = 2, 11/03/2010 = 3, etc.) then simply sorting those by timestamp and putting them back in the list.

Also if each of these blocks could be done on its own cpu core to utilize the multi-core cpus that would speed it up a lot too. That shouldn't be a problem if a single control list is made with each "by date" block numbered so the sorted info could be put back into the thumbnail list properly.