x11vnc refresh is slow when using XUbuntu desktop

[Matthew Caron]

When viewing the desktop exported via x11vnc, refresh rates are slow.

1.) This happens irrespective of client / client machine (Remmina, TightVNC viewer, RealVNC viewer), so it's not the client.

2.) iperf shows 900mbps+ bandwidth between clients and server (gigE wired connection).

3.) Refresh rate gets worse as screen resolution increases (HD is reasonably usable, say 500ms between refreshes based on looking at gkrellm graphs, but 4K is more like 3 seconds between redraws).

4.) It does not do this if logged in to a Mate desktop, leading me to believe it's XFCE, not x11vnc.

5.) This worked fine on 18.04, at 4k - no discernable lag. Everything else remains the same, just this was updated from 18.04 to 20.04.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: xubuntu-desktop 2.233
ProcVersionSignature: Ubuntu 5.4.0-42.46-generic 5.4.44
Uname: Linux 5.4.0-42-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu27.6
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: XFCE
Date: Mon Aug 17 00:21:10 2020
SourcePackage: xubuntu-meta
UpgradeStatus: Upgraded to focal on 2020-08-12 (4 days ago)

[scuba (scubuntu)]

same issue here after upgrading xubuntu 18.04 to xubuntu 20.04.
tried to resolve the issue by reconfiguring X11vnc, issue was not resolved
tried to resolve the issue by lowering resolution to '1024x768' and '1280x960', issue was not resolved

this issue persists

[Sean Davis (bluesabre)]

Since this seems to be an Xfce-related issue, reassigning to the most-likely xfwm4 package.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[McPeter (mcpeter)]

Hi! i solved this problem with "-noxdamage" argument in x11vnc command line