Public bug reported:
Component: grd-rdp
GNOME Remote Desktop version: 50.0-0ubuntu2 (Ubuntu 26.04 / Resolute)
Kernel: 7.0.0-22-generic
Mesa / GPU / driver: (please fill in — glxinfo -B or ubuntu-drivers list
--gpgpu)
Client: Microsoft mstsc.exe, Windows (version: __)
Network: (LAN / WAN / VPN — please specify)
Summary
When connecting from Microsoft mstsc (Windows) to gnome-remote-desktop's
RDP server, the session becomes effectively unusable at the default 32-bit
color depth. Switching the client to 24-bit color only partially mitigates the
problem.
Steps to reproduce
1. Fresh install of Ubuntu 26.04 with gnome-remote-desktop 50.0-0ubuntu2.
2. Enable RDP via GNOME Settings → Desktop Sharing / Remote Login, or
grdctl rdp enable.
3. From a Windows client, launch mstsc.exe, connect to the host, accept the
certificate, log in.
4. Default client color depth (32-bit / True Color): drag windows, scroll
in an application, type in a text field.
5. Disconnect, reconnect with client color depth forced to 24-bit, repeat.
Expected
Responsive frame updates and low input latency at both 32-bit and 24-bit
color depths. Microsoft mstsc against Windows Server / Windows peers reaches
30–60 fps on similar hardware with no special tuning.
Actual
- 32-bit: severe, session-wide slowdown — (describe: frame drops / input
lag / tearing / specific). With Unity running, essentially unusable.
- 24-bit: improved but still noticeably worse than expected. (Describe how:
still input laggy? scrolling still choppy? what specifically improves vs. what
doesn't?)
- Pattern is consistent on Unity (a GTK/SDL/Xwayland-heavy workload) and on
a fresh GNOME session.
Daemon log (journalctl --user -u gnome-remote-desktop)
^[[56;1R^[[55;1R
gnome-remote-desktop-daemon[10229]: [HWAccel.Vulkan] Initialization of
Vulkan was successful
gnome-remote-desktop-daemon[10229]: RDP server started
Hardware acceleration appears active, so this is not the "no GPU path"
failure mode.
^[[56;1R^[[56;1R^[[56;1R^[[56;1R^[[56;1R^[[56;1R
GSettings (org.gnome.desktop.remote-desktop.rdp)
All defaults — auth-methods=['credentials'], enable=true, port=uint16 3389,
screen-share-mode='mirror-primary', view-only=false, negotiate-port=true. No
custom tweaks.
What I've already tried
^[[56;1R - Forcing 24-bit color depth on the mstsc client → only marginal
improvement.
- Verified HWAccel.Vulkan initialised in the journal (above).
What I have NOT yet tried (please tell me if any of these are worth running
before you file):
- Disabling HWAccel via HARDWARE_ACCEL_DISABLED=1 env on the daemon to
compare a software path.
- RDP_DEBUG_FPS=1 / RDP_DEBUG=ENCODER style tracing, if the project
supports them — happy to capture and attach.
- A perf / sysstat recording of gnome-remote-desktop-daemon during the
slowdown.
Hypothesis (low confidence, included to help triage)
The 32→24 improvement suggests the cost is in the frame encoder path, not
the network. With HWAccel.Vulkan initialised, the question is whether the
encoder is actually using the GPU backend in this build, or falling back to a
slow software path despite successful init. A second possibility is
mstsc-specific — its RemoteFX / GFX PDU negotiation may be pinning us onto a
sub-optimal encoder (e.g. planar RFX vs. progressive).
ProblemType: Bug
DistroRelease: Ubuntu 26.04
Package: gnome-remote-desktop 50.0-0ubuntu2
ProcVersionSignature: Ubuntu 7.0.0-22.22-generic 7.0.0
Uname: Linux 7.0.0-22-generic x86_64
ApportVersion: 2.34.0-0ubuntu2
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Fri Jun 5 13:16:38 2026
InstallationDate: Installed on 2026-01-20 (136 days ago)
InstallationMedia: Ubuntu 25.10 "Questing Quokka" - Release amd64 (20251007)
ProcEnviron:
LANG=en_US.UTF-8
PATH=(custom, no user)
SHELL=/usr/bin/zsh
TERM=xterm-256color
XDG_RUNTIME_DIR=<set>
SourcePackage: gnome-remote-desktop
UpgradeStatus: Upgraded to resolute on 2026-05-01 (35 days ago)
** Affects: gnome-remote-desktop (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug resolute third-party-packages wayland-session
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https://bugs.launchpad.net/bugs/2155640
Title:
gnome-remote-desktop is way too slow on two separate Ubuntu 26 lts
machines
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