Minecraft TPS are at 14-18?

No matter how hard I try, the TPS from my server is around 18.

If I don't have any plugins at all, the TPS when no one is on it are: * 20.

But if someone comes up and I don't have any plugins, they are at: 19.12 or so.
As soon as 1 plugin is added, the tps land at 19.15 if no one is on it.

if someone comes up who I have 1 plugin on, the TPS are: 18.

I don't understand it anymore!

Version: Spigot 1.12.2
RAM: 2GB
CPU: It doesn't matter because it runs stupid everywhere.

Too little RAM…

The Max TPS are 20. 18 is totally fine. RAM has nothing to do with TPS and has no influence on it. From a value of approx. 15 TPS, lag is noticeable.

RAM has no influence on the TPS if it hosts the server by itself and has too little RAM it will simply crash but without lags.

No, if more ram is needed, a Linux system will use the hard drive. And then it gets slow.

Does he have a Linux system and could you counteract this with a virtual ram?

80-90% of the servers on the Internet run on Linux. Unless otherwise stated, I assume.

That swings half way, sometimes I have 13

And I would also say 2GB for 1 plugin should be enough

Windows uses the hard drive as well, there should be no more RAM available as far as I know

I would not be sure, I would expect.

CPU:
It doesn't matter because it is stupid everywhere.

So did you try another processor?

Yes, different devices

There are the tps and my plugins

How long do you leave the server on to check the TPS?

What are the built-in devices for processors?

1 - 10 minutes