Zend certified PHP/Magento developer

Why is VNC so slow?

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.