SharePoint Document Library speed?

Hi Ahmad123,

I have never worked with such a huge single library. For all my projects I used retention policies and automation to keep documents and records ordered. Anyway, the Library's perfromance depends on many parameters, such as configured indexing, views configuration, number of items per view / per library, etc.

https://support.microsoft.com/en-us/office/manage-large-lists-and-libraries-in-sharepoint-b8588dae-9387-48c2-9248-c24122f07c59?redirectsourcepath=%252fen-gb%252farticle%252fmanage-large-lists-and-libraries-in-office-365-b4038448-ec0e-49b7-b853-679d3d8fb784&omkt=en-us&ui=en-us&rs=en-us&ad=us, you may find some clues about configuring large libraries.

Theoretically, the difference between 120K and 600K items per library in terms of performance could be noticeable. I afraid, it's inevitable.

However, you may improve the performance with better views configuration, indexing and automation to keep the number of items per library reasonable (if applicable).

Best of luck!