Reducing lag in a building game

I have been working on a building game, and I found that after making a new saving/loading system for it worlds players created in the game that previously was completely performant have now become laggy for players (these worlds have around 1k+ Blocks/Parts)

I am uncertain of the cause or ways I can solve this issue, I have tried looking to make sure the system isn’t making duplicate blocks by chance but that doesn’t seem to be the case and I have looked at the console to determine whether or not it was memory usage but it doesn’t seem to be that either.

this is the game having said issues with laggy worlds (an example of a world in it having issues would be the one with the id of 5058991411)

Game might become laggier depending on how many requests you make from the client to the server and vice-versa from a network lag perspective.
If you’re talking about FPS then, this could be because of a poor optimization on the local scripts or because the client’s computer cannot handle rendering a game with more than 1k parts in it.

it’s the FPS, before I made the new saving system those worlds with 1K+ Parts/Blocks were running perfectly fine however this new system seems to have made it laggy for whatever reason, it can’t be mine or anyone else’ computers since as I said before they were working perfectly fine

What were the changes you made to this, saving system?

How do you save the parts exactly. Surely it must be the method you use.

I used to save them and load them from a datastore but I changed to use createplaceasync so I didn’t have to load them all at startup every time

Are you using Serialization for saving multiple parts?

I am using saveplaceasync (30 characters)