Performance without ubuntu resource

Hello. I’m a newbie on nvidia board.
I worked without ubuntu or any gui environment in other board.
I have doubt ubuntu resource will affect to overall jetson system performance.
Can someone explain why jetson tx2 using ubuntu gui resource and if I can get more good performance without ubuntu resource?
We are not using display in jetson board and just running our algorithm(cpu, gpu).

You don’t need lightdm or window management software, but what many people don’t realize is that X11 is an interface to the GPU in general, and is not merely for connecting a monitor. Much of the software out there expects X11 as the API on top of the video driver. The buffer the driver works with is normally set up via the “DISPLAY” environment variable which X11 sees. It just happens that desktop GUI software is present by default. You could put in a virtual X desktop (such as for desktop sharing), and this too would provide that DISPLAY environment…but it wouldn’t be running a real monitor.

The desktop itself, lightdm, and anything you may think is X, probably is just a program being run in X…X itself has no such requirement. X runs a single application…if that application happens to be a window manager, then what you get is a full desktop. That application could just as easily be “xterm” and your entire desktop would be “xterm” without any of the desktop multitasking amenities. X is a protocol and API operating on a buffer which usually is in a graphics card. It isn’t a desktop or GUI in and of itself.

You might find interest in this related forum thread:
https://devtalk.nvidia.com/default/topic/1036010/jetson-tx2/underflow-using-pal-720x576-hdmi-video-output/post/5263098/#5263098

Trivia: CUDA is tied to the NVIDIA video driver. The NVIDIA video driver is tied to a specific Xorg ABI (“gawk ‘/Module ABI versions/,/using VT number/’ /var/log/Xorg.0.log”). The DISPLAY environment variable names which Xorg server sees events related to manipulation of the buffer…remote display via X forwarding offloads that work to the other computer…remote display via a virtual desktop keeps the work on the Jetson since X events talk to the Jetson’s server instead of the remote system. Xorg manipulation of the buffer is through the interface to the video driver. A user not in group “video” does not have access to the GPU, and thus will see X login problems…which in turn means CUDA failure just as if the program had been a GUI program.

Okay I will fix my question.
If I don’t need to window manager(I think it can be a process that use system resource), can I expect more performance?
I mean, If below setting is added to my system, can I expect better performance then before?
https://devtalk.nvidia.com/default/topic/1036010/jetson-tx2/underflow-using-pal-720x576-hdmi-video-output/post/5263098/#5263098

Because we are doing many things each cpu and gpu, really want to optimize tx2 environment.

Obviously any reduction in competition for resources could help, but it is difficult to say how it might help without knowing exactly what is going on…perhaps more information on your specific case would help. The first thing to do would simply to be sure the energy saving modes are off. If you are testing performance start with this:

sudo nvpmodel -m 0
sudo ~ubuntu/jetson_clocks.sh

Can you give some specific ways you are using I/O, CPU, and GPU? Is there one particular case which stands out as needing optimizing?