I am running an X11 application on a RHEL machine on my Windows system using Xming and X11 forwarding over SSH. The responsiveness seems terrible. A second between keystrokes and mouse clicks, etc. When I ping the linux box from my windows machine, I can see the latency is only about 85 ms. I have enable ssh compression and set my cipher to suggested setting. It has helped a little, but it is still pretty bad. How do I diagnose why the responsiveness is so poor? Are the utilities I can run under windows (or linux) that will track the latency of all network packets between the two machines?
The problem is that the X11 protocol is fundamentally unsuited for this because it is incredibly chatty in both directions and only really works well with local connections with much lower latency. Modern graphic intensive GUIs and toolkits made the problem only worse as they create much more data in the protocol compared to old xlib or Motif apps.
I would consider alternatives/improvements like NX or xrdp, which work much better over high-latency connections.