Severely jammed servers

Server broadband is 100MB dedicated line
Original server configuration.
Intel i5-4460 CPU 3.2GHZ
Memory 8g
SSD hard disk 120g
MC server configuration: 5g running memory.
When running multiple servers, all four CPUs are in use.
And the system never reported a delay!
14 players online, average CPU 20-30%
I recently bought an old server.
Server configuration:
Intel E5 2680 v2 2.8GHZ
Memory 32g
SSD hard disk 120g
MC server configuration: 6G running memory
CPU and online players are shown below

All data and archives are migrated from the original server.
Don’t tell me how many MODS and plugins are installed.
Because I didn’t add any MODS and plug-ins after migrating the data.
Please also do not let me provide time reports.
Because there’s never been a carton problem reported on the original server.
I just like to know what is the cause!
Now there are only three online players.
I started to report performance shortfalls. How can I face and solve problems?
I’m pretty disappointed with Minecraft right now.
Oh, no! I’m breaking down. Please help me

I was just writing plug-ins for my server.
Now I have to stop working on it to solve this problem

So your new processor on a per core level is slower then your older processor. Minecraft itself doesnt really take advantage of multiple cores as most actions require to be synced, therefore the best option for running a single server is to have the best single core performance.

Your new processor is faster for programs that take advantage of multiple cores, therefore in theory you could run more servers and not have a performance impact as each server is dedicated to a single core, while your previous server would only be able to dedicate 4 servers to each core (as its a 4 core processor), anymore and then the servers would be sharing a core.

You can see that minecraft is primarily a single core program as shown by your taskmanager, core 5 is taking most of the heat. It looks like cores 1-4 also have the other servers on (including the bungee - or whatever server proxy you use).

You can see the difference in single core performance between the two processors here (assuming your Intel E5 is version 1 (there are 3 versions with the same name)) Intel Xeon E5-2680 vs Core i5 4460

Hope thats the info you wanted

May I ask if I turned on the virtual machine? ?
Number of physical cores 4 Number of virtual cores 16. Is it possible that the virtual machine caused the problem?

Typically virtual machines will run on one of the cores that you assigned to it (there are exceptions). So by all means try running the servers as close to bare metal as possible to see if it helps, however due to the processor being weaker on a per core bases, its likely it wont fully “fix” the issue

I’ll give it a try! In mod or plug-in development, is it possible to have some unimportant events run on another thread? ?

Within plugin and mod development it is possible to code anything onto another thread, the issue is if any code interacts with the Minecraft world from another thread (hardware threads are inside core (also something called software thread but I wont go into that)) then the mod/plugin will crash.

So in short, yes, as long as you dont interact with the world, so stuff like chat can be done asynced