Test system: ARM64 Ubuntu Jammy and Ubuntu Noble
Default Ubuntu GNOME desktop environment used with no user added extensions.
GPU driverstack identical between the two distros (eliminated as a variable).
Linux kernel identical between distros (eliminated as a variable)
CPU, GPU, and RAM clocks pinned to max.
Test case: Minecraft Java Edition (shared drive with identical setup between Ubuntu versions). Fullscreen 1080p. Xorg display server.
Observations:
Ubuntu Jammy:
gnome-shell process cpu% when camera is still: 0-1%
gnome-shell process cpu% when camera is moving: 10-20%
Memory Bandwidth (CPU and GPU shared): 40%
Ubuntu Noble:
gnome-shell process cpu% when camera is still: 20-55%
gnome-shell process cpu% when camera is moving: 30-55%
Memory Bandwidth (CPU and GPU shared): 50%
In both cases GPU utilization is observed to be near 100%.
So in summary, large performance regression regression which appears to be due to gnome-shell. There is nearly no gnome-shell cpu% usage on ubuntu jammy when there the camera is still (even with a fps graph drawn onscreen) in stark contrast to ubuntu noble.
Test system: ARM64 Ubuntu Jammy and Ubuntu Noble
Default Ubuntu GNOME desktop environment used with no user added extensions.
GPU driverstack identical between the two distros (eliminated as a variable).
Linux kernel identical between distros (eliminated as a variable)
CPU, GPU, and RAM clocks pinned to max.
Test case: Minecraft Java Edition (shared drive with identical setup between Ubuntu versions). Fullscreen 1080p. Xorg display server.
FPS (uncapped):
Ubuntu Jammy: 177fps
Ubuntu Noble: 140fps
Observations:
Ubuntu Jammy:
gnome-shell process cpu% when camera is still: 0-1%
gnome-shell process cpu% when camera is moving: 10-20%
Memory Bandwidth (CPU and GPU shared): 40%
Ubuntu Noble:
gnome-shell process cpu% when camera is still: 20-55%
gnome-shell process cpu% when camera is moving: 30-55%
Memory Bandwidth (CPU and GPU shared): 50%
In both cases GPU utilization is observed to be near 100%.
So in summary, large performance regression regression which appears to be due to gnome-shell. There is nearly no gnome-shell cpu% usage on ubuntu jammy when there the camera is still (even with a fps graph drawn onscreen) in stark contrast to ubuntu noble.