Very high CPU usage on folder "synch"

I have folders full of images on websites that I often have to synch with a local copy.
I do a visual compare in SFTP and upload the difference.
These folders are around 4000 images.
I get VERY slow uploading when I do this and cpu usage for the program is taking up 1 of my cores on the CPU.

This is holding me back from buying an otherwise great program.
Any ideas?

Hello ..

Comparing 4000 files takes a long time. I recommend you install the latest version from here:

Then close the Remote Browser when the upload starts.

If you don't want the Visual Compare feature just disable it and you will have the same speed as in other basic ftp clients.