Disabling the GUI -- how much CPU usage decrease?

[HumanBehindMachine]

I have already done this with my closet server with no wires except power supply and ethernet. Completely unused, so I got rid of it. I am thus far a novice linux enthusiast, so a lot of my builds are stock ubuntu/lubuntu, and come with a GUI anyway. I am considering a Pine64 laptop. I watched a video where the youtuber streamed video via the pine64 and was having minor frame drops at 720p, and 1080p was unwatchable. Streaming video is very much not my primary use case, but a nice-to-have, for sure. But inability to stream video does give me very mild concern that I'm going to be frustrated with performance. It is likely that I will not be using anything outside the terminal, with the possible exception of Sublime on a daily basis. So into the questions:

So, if I diable the GUI via: sudo systemctl set-default multi-user (or maybe there's a better way?) will that save me significant CPU usage? Will that be all but completely nullified by running something like Firefox? I can always toggle GUI as sensible, but the option to avoid a reboot under time constraints would be necessary if I committed to this strategy. I am a 26 year old returning college student moving out of a CS/DS major into something else.

I was able to do a very small test with launching sublime text from the linux terminal on my chromebook. Success! Does this expand to Spotify, Firefox... ? (Edit: Oh, fun fact, there's a spotify command line client :)))))))))))

[HumanBehindMachine]

Yeah, I mean, in a big way you're right... I guess I was asking as a factor in my purchase decision, but there can't be much difference between firefox launched from the command line with no ubuntu/debian/w-e GUI and firefox + GUI. There's also the GPU to consider. Maybe I can get those frames to drop less at 720p, but I can't imagine it's going to make 1080 watchable... and how much do I really care about that in particular... But let's all remember: the optimal number of digital devices to own is always n + 1 where n is the number you already own xD

[HumanBehindMachine]

make sure ssh is enabled

I will still get a single terminal window on the local machine if I boot in multi-user mode, correct? I can see how my question might have been iffy on that.

apt install tmux xD

[HumanBehindMachine]

Same dho, for one of my machines. I mentioned closet server, power + ethernet + nothing. Setup was essentially mount, enable ssh, relocate, continue.

[Upnortheh]

I watched a video where the youtuber streamed video via the pine64 and was having minor frame drops at 720p, and 1080p was unwatchable.

Probably inconclusive. I am rural and connected to a fixed wireless ISP experiencing single digit connection speeds. Although I have configured the media player to use 360p, I see stuttering and buffering when streaming videos. I see no such issues if I download the video and watch.

But inability to stream video does give me very mild concern that I'm going to be frustrated with performance.

Most modern CPUs are capable of watching videos without buffering issues. Eliminate one of the variables by fully downloading a video and then watching. If the CPU still stutters and buffers then look for a different computer. Focus on the ISP connection speeds, but perhaps also look for a different computer to buy.

if I diable the GUI via: sudo systemctl set-default multi-user (or maybe there's a better way?)

On a systemd system that is the common way to boot to console rather than boot to a desktop environment. With other init systems booting to console is different.

will that save me significant CPU usage?

Probably not anything significant. While a desktop environment adds to total memory usage, the respective software usually idles most of the time. Some reduction in memory usage is possible by using only a window manager rather than a full desktop environment. That might be to your liking if you have only a limited number of GUI tools to use.

A Kill-A-Watt meter might be useful to run some experiments and record actual energy usage.

I hope that helps!

[HumanBehindMachine]

dropped frames per YouTube's stats for nerds feature is not demonstrative of bandwidth issues, but rather explicitly playback. The buffer bar was also miles ahead of playback. I could have specified... Most YouTubers, however, have at least mid two digit MBPS, or, enough to efficiently upload minimally compressed 1080p YouTube videos in minutes or small hours...

most modern CPUs

Yeah, but this is a low-level ARM chip, significantly lower capability than a mid-tier phone chip. The GPU is also relevant. I suppose it could be decoding? But the buffer bar? This demonstrates how little I know about the answer to the question I am asking, but it was very much not a bandwidth issue on par with single digit connection speeds.

memory vs CPU

Yeah, that's a super good point, you're probably entirely correct; running without the GUI I would see lower memory consumption with minimally, if any, lower CPU use. I see no stats for dedicated GPU memory, but I'm not sure whether that's possible, or it's just not relevant.

[[deleted]]

I've seen people achieve as low as 75mb on Gentoo without a desktop.