I saw a post that you cured someone of some slowness by fixing something in libpcap. Hoping I would see the same results, I went ahead and did a fresh install of CentOS 7 and ShowEQ 6 on a Raspberry Pi 4-4G.
Same slowness, without even sniffing packets yet. I'm forwarding the X11 display over SSH from the RPI to a laptop. Poking around, I saw that sshd was taking 25% utilization. Interesting. So I decided to do the X11 forwarding without ssh. Still slow.
I wanted to see what was going on with the network, but I couldn't find ntop for arm, so I just went ahead and looked at my laptop's task manager, and here's what I found.
ShowEQ 5 with QT3 exporting the display to the laptop uses almost zero network bandwidth: 0.1Mbps
ShowEQ 6 with QT4 exporting the display to the laptop uses about 800x the bandwidth: 82.9 Mbps
I have zero idea what could be causing this, but I figured you'd be interested in seeing what I'm running into. Perhaps not many others are exporting their display to a remote machine which is maybe why you haven't heard any other people complain? I'm using Xming, an X server for Windows as well as XQuartz, an X server for MacOS. Both show the same issue.
And maybe this is a problem everywhere, but is hidden by the fact that most PCs can probably handle this sort of graphics locally?
Here's some screenshots of Windows task manager reporting the network utilization of the X server:
https://i.imgur.com/4Ws9wDN.png
https://i.imgur.com/U7NJHAf.png
I hope that offers you some insight as to what might be going on. I can't make any sense of this at all.
Thanks