CPU GUI lagg unplayable ticks skipping can t keep up

After adding the NOGUI Option to Startscript, CPU usage droped significant 40 to 2% Idle 80 to 8 1player.
The Server becomes playable. no lagg, faster chunc loading, big Mobs no longer cause lagg. railroading smoth. no loading lagg holes in world. and Server now uses 5G ram full. arround 1g bevore with same startscript exept nogui. minecraftserver exe wont work properly, Java Version on Windows does fine.