Often Dolphin is incredibly slow to the point where it is impossible to scroll (and there aren't that many files). Right clicking to pop up a menu may take several minutes to respond. Top does not indicate any significant system activity and dmesg reports no issues. This is on a machine with a 1TB SSD. Copying files is also taking over 30 minutes using copy/paste whereas the cp command finished copying the files in 45 seconds. I see no reason why Dolphin should be so slow. The copy operation was between a high-speed compact flash card and my hard drive over a USB 3 connection.

Even changing directories to an empty folder takes an incredibly long time as does creating a folder. The hard drive is formatted with XFS on a high-speed SSD.

Reproducible: Sometimes

Steps to Reproduce:
1. Open two instances of Dolphin
2. Move the first instance to the source folder
3. Move the second instance to the destination folder, creating folders as necessary where the files should be placed. The operation is very slow.
4. Select files in the first instance of Dolphin and copy them. The first instance is fast and operates as it should be.
5. Select paste on the target directory to copy the files
6. Wait.......

Actual Results:  
Operations complete but they are extremely slow, often taking many seconds to complete.

Expected Results:  
The results of changing directories and creating directories should be nearly instantaneous and copying files should be relatively fast

Hard disk is not fragmented much and is not very full. Command line is quite fast. The source folder contains several GiB of large Nikon raw image files (NEF). Each file is roughly 36MB.