I connect from the TigerVNC client on MacOS to an x11vnc server running on Linux.
When the connection speed is 6 Mbps on the client side and 100 Mbps on the server side it takes 7+ seconds to update the screen when it has a complex picture. I did a screenshot on this picture and the file size is 800k. 800k with a 6 Mbps connection should be transferred in ~1 sec.
Why does it take VNC many seconds to transfer a picture that should normally take ~1 sec?
Maybe VNC does many round trips to transfer picture chunks?
Maybe some VNC options are wrong?
Maybe there are some bugs?
These are my guesses.