I need to work on a GUI on a remote Linux (CentOs) server (I measured with
iperf a ~8Mbits/sec connection between these two machines). I always used
ssh -X instead of VNC for this since:
- I need to open only one window so I like to have it as a window as if I opened this program on my computer
- I can use my SSH key for this
- I want the software to adapt to the size of my desktop, not the virtual VNC desktop (though I guess there are options for that with VNC)
But here what appears is that using my GUI with VNC is a lot faster than with SSH -X, I see a lot more quickly the changes in the GUI when I use it so I'm kind of obliged to use it.
It seems to me that VNC just sends a compressed image of the part of the screen that changes which is a lot faster than SSH that need to send all informations to me.
For instance with ssh -X it takes 5 to 10 seconds to react to me clicking to the 'File' menu of Firefox and display it. With VNC there is no visible delay.
So my question are:
- Is VNC expected to be a lot faster than ssh -X?
- If not, how can I troubleshoot to see why ssh -X is so slow?