Increase pagefile size • Link
Final Fantasy XV uses heavy resources on a PC's paging file, which acts as alternate virtual RAM.[12]
If the paging file is set too low (such as a maximum of 2 GB), this can act as a performance bottleneck, resulting in frequent stutters while exploring. This is especially true if the system's RAM is 8 GB and under. Increasing the paging file size (such as from 2 GB to 8 GB) can drastically improve performance and reduce stutters.
Increase pagefile size
Open start menu, type "run" and use run command.
Enter systempropertiesadvanced. Go to "Advanced" tab and click settings.
Go to "Advanced" and choose "programs" instead of "background services".
Under virtual memory, click change. Uncheck "Automatically manage paging file for all drives" at the top.
Select custom size. Although there is no definitive paging file size, try making the initial and maximum both 12288.
Click OK and restart your computer. Try the game to see if performance is improved.