Game Performance Slowing Down looking for help

[Delzarin]

Hey everyone,

I’m hoping someone here can help me out. I’ve been playing Stellaris for quite a while, and I’ve never had any issues with performance. Back when I was on version 3.14, the game ran perfectly, even with a gigantic galaxy and 30+ countries. It only took about a second for a month to pass on the fastest speed, and everything was smooth, even in the late game.

But after upgrading to version 4.0.20, it’s a totally different story. Now, the game is ridiculously slow. Each month takes about 2-3 seconds on start, and when the Galactic Community starts in a gametime, a single day can take 1-2 seconds. It’s become a real grind, and it’s hard to enjoy the game like this.

I’ve checked my performance, and my CPU (AMD Ryzen 7 7800X3D, 8-core, 4.20 GHz) is only being used at about 40%, even when the game is running slow. It’s not maxing out, so it seems like Stellaris isn’t even using the full power of my CPU, which seems weird. I checked every core, there is no even one core that will be used on max.

I also tried running the game without any mods, and it’s still way slower than when I was playing on 3.14. I’ve updated all my mods to be compatible with the new version of the game, and they’re the same mods I’ve been using for months. So I don’t think it’s a mod issue, but maybe there’s something deeper going on.

Has anyone else been dealing with this slowdown since the 4.0.20 update? Is it something specific to the patch causing the lag in the later game? I’m honestly at a loss here, and I’m hoping someone might have some advice or tips on what I can do to fix this.

Thanks in advance for any help — it’s been frustrating trying to play with this constant lag.

My mods list is attached. Sorry it was the best way that I can find to shyow the mod list.
 

[Rollar32167]

It's a problem with version 4.0+. The devs believed that the new planetary systems would vastly improve performance, and it hasn't (as of yet). From keeping up on the comments on Reddit, apparently the only way to counter it is to exterminate and leave empty planets, as well as keep there from being too many ships around.

I personally still play 3.14, as only the latest 4.00 patch has started to fix the AI (which has been severely gimped since 4.00).

[Delzarin]

On 7/14/2025 at 10:30 AM, Rollar32167 said:

It's a problem with version 4.0+. The devs believed that the new planetary systems would vastly improve performance, and it hasn't (as of yet). From keeping up on the comments on Reddit, apparently the only way to counter it is to exterminate and leave empty planets, as well as keep there from being too many ships around.

I personally still play 3.14, as only the latest 4.00 patch has started to fix the AI (which has been severely gimped since 4.00).

Thanks for your answer. I was searching information also, but I think I was really hoping that this is  something that I am messed up, than that is really state of the game.
I was thinking come back to the 3.14 but not all mods that I am using have available to download version for 3.14 so, I stuck here.