Swarm performance using old servers


For the purpose of speeding up light building we got 2 used servers with 2 Xeon E5-2695 V2 (12 core 24 threads) processors each.
Beside them we have also 2 desktops with i9-11900F (8 cores 16 threads).
Every machine has 128gb of ram memory.
I have Swarm Agent running on all of them and one i9 with the Swarm Coordinator. They all can ping each other.

I’m using this command line to build lightning:
“PathToTheEngine\Engine\Binaries\Win64\UE4Editor-Cmd.exe” “C:\GameDir\MyGame\MyGame.uproject” -Run=ResavePackages -BuildLighting -Quality=Preview -MapsOnly -ProjectOnly -AllowCommandletRendering -Map=MyLevel -Messaging -stdout

The issue I have is performance when using servers to build lighting.

I did test different combination but one i9 is starting the build always.
When building only on one i9 it takes 2003.87 seconds to finish.
When using swarm:

  1. with two i9 it takes 1193.30
  2. with one i9 and one server it takes 2100.02
  3. with one i9 and two servers it takes 1904.70
  4. with two i9 and two servers it takes 1330.16

I understand that these servers are pretty old but what I do not understand is why they are slowing the build.

This is how Swarm Status looks like on main machine:

Does anyone have experience in similar setups?

Thanks in advance!