[0.14.22]Weird multiplayer performance problem

[Hetshu]

We are playing an 1 RPS factory multiplayer game with 2 players on local LAN on current version 0.14.22
One player is server, the other is client only. No headless server is involved.
We are using quite new, high end, identical computers.

We discovered that the player which is playing as client uses way more CPU ressources then the player which is hosting the server and usually
gets into UPS problems first in later game states. (In early game phases this isn't noticable)
We accepted this behaviour so far as a strange factorio feature, as it happened in all our multiplayer games so far (slighlty modded and heavily modded)

Now for the interessting part:
If the player which is playing on the server computer sets the debug mode "show_active_chunks" via F4 menu, then the extra CPU load on the client computer vanishes and both games result in similar UPS (Actually the server has a bit less UPS than the client now).
If the server player disables show_active_chunks again, the UPS on the client computer drop again.

We checked with show_time_used_percent mode, if a special mod is responsible for this behavior and this is not the case.
If "show_active_chunks" is set to off on the server side, all update times just rises on the client side, distributed proporionally on game update and script update times.

I dont know, if this counts as a bug. I found it peculiar enough to report it here.

I am happy I found this out and play in show_active_chnunks mode on the server by default from now on

[Smarty]

please provide both logs and the save

[Loewchen]

...and read the Known issues - READ BEFORE POSTING section.

[Hetshu]

please provide both logs and the save

here we go:
https://www.dropbox.com/sh/4nohw99imkge ... -bNta?dl=0

[Rseding91]

Your save file is simply too large with too much going on such that everyone connecting can't keep up with it. When you enable the "show active chunks" option on the server side it forces the server to do that logic which slows it down enough for people to play.