Hi @Amy Harrison ,
Which version of SQL Server do you used? Because there have memory limitation for different version of SQL Server, you can find the details form this link.
When SQL Server is using memory dynamically, it queries the system periodically to determine the amount of free memory. Maintaining this free memory prevents the operating system (OS) from paging. Please find more details from this link.
Best regards,
Carrin
If the answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.