To keep the article precise, here are the definitions I use:

• Tick: The time your PC needs to calculate one in-game day.
  
  
• Micro-lag: Lag that is not recorded by the in-game tick/debug tool. It appears as short freezes, even when the game is not paused.
  
  
• Initialization time: The time needed to fully load and stabilize the game in the first week. This is a crash-prone period, especially when using many mods.
  Workaround: Save the game every day before the 14th of the first month and use pause after each day to avoid crashes.

The game has an internal limit of how many star systems can be generated:
Approximately 2431 systems is the safe maximum using default settings.

As of 10.07.2025, I tested various mods to increase this number. Only one worked reliably.
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1986046755

• CPU: 13th Gen Intel(R) Core(TM) i7-13700KF @ 3.4 GHz, 16 Cores, 24 Threads
  
  
• Motherboard: Z790 AORUS ELITE AX
  
  
• GPU: NVIDIA GeForce RTX 3080
  
  
• Storage: WD Black SN850 1TB NVMe SSD
  
  
• RAM: G.Skill DDR5 64GB (2x32GB) @ 6000 MHz

Default Galaxy (2431 systems)
https://i.imgur.com/TkCcv4z.png

• First-month tick: ~34ms
  
  
• Year 550 tick: ~400ms
  
  
• No visible micro-lag
  
  
• Time of save loading: ~1 mins

20,000 stars: Crash during generation.

15,000 stars:

https://i.imgur.com/7bwuvqr.jpeg

• Generation time: ~14 hours
  
  
• Initialization: Extremely slow
  
  
• Severe micro-lag
  
  
• Only playable for people with extreme patience
  
  
• Time of save loading: ~2 hours

10,000 stars:
https://imgur.com/a/10k-star-system-stellaris-1gTcuyz#tTeOXkc

• Generation: ~1.5 hours
  
  
• Initialization: ~30 minutes
  
  
• 1 crash
  
  
• Tick at start: ~80ms
  
  
• Noticeable micro-lag, ~2 seconds to unfreeze
  
  
• Time of save loading: ~15 mins

7,500 stars:
https://i.imgur.com/wxV9iSX.png

• Generation: ~1 hour
  
  
• Initialization: ~20 minutes
  
  
• Tick at start: ~55ms
  
  
• Playable, minor micro-lag
  
  
• Time of save loading: ~9 mins

5,000 stars:
https://i.imgur.com/eybUuAs.png

• Generation: ~15 minutes
  
  
• Initialization: ~10 minutes
  
  
• Tick at start: ~42ms
  
  
• Nearly invisible micro-lag, smooth performance
  
  
• Time of save loading: ~5 mins

Thanks for reading my research. I hope this helps you make an informed decision when planning your next long campaign. Choose wisely — bigger isn’t always better!