Best approach for: Dual boot Mac OS and Win 10 And shared files volume I've got a somewhat older macbook pro (mid 2014) and it starts lagging. And since I'm working professionally on it I'm thinking of buying a new macbook or Win laptop. But since I never had a clean install I first want to try a few things.

Clean up internals, new cooling paste and clean OS install. But since I'm also thinking of switching from Mac to Windows I also want a dual boot of Win10. So I can try working with Windows for a month. Since I will be switching between operating systems I want to have an additional volume for all my work files.

But I'm not sure how to partition the 1tb ssd.


What partitions would I need and what type
Would there be performance issues working on a volume type that one of both don't prefer?


I'm thinking of, first make 3 volumes, install Mac OS, then on create a boot camp with Boot Camp Assistant. 

Any help would be welcome
Steps to do a clean install of macOS and Windows

To do a clean install of the current versions of macOS and Windows, preform the following steps.


Boot to a macOS installation media. For example, this could be a Mojave recover volume, internet recovery or a installation flash drive.
Use the Disk Utility to erase the drive and create a single APFS volume.
Install Mojave to this volume.
Use the Boot Camp Assistant to install Windows 10. Include space for the MS-DOS (FAT) or ExFAT volume to be shared.


Steps to create a shared volume


  This is to be done after installing macOS and Windows.


To create a MS-DOS (FAT) or ExFAT volume to be shared, preform the following steps.


Under Windows 10, open Disk Management. Highlight the BOOTCAMP volume and select Shrink Volume…, as shown below.


Select the desired size, as shown below. Next, select the Shrink button,


Highlight the unallocated space and select New Simple Volume…, as shown below.


When the image shown below appears, select the Next button.


When a image similar to the image shown below appears, select the Next button.


In desired select a different drive letter, then select the Next button.


Select FAT32 and enter a volume label, as shown below. When finished select the Next button.


When a image similar to the image shown below appears, select the Finish button.


The result is shown below.


If you wanted ExFAT format, then restart back to macOS. Use the Disk Utility to erase the volume. Enter a name and ExFAT format, as shown below. When finished, select the Erase button.




Note about the Golden Rule

There is a Golden Rule which can be loosely stated as:


  Never change the partitioning on a Mac from Windows.


In this case, the Golden Rule does not apply for the following reasons.


There no Mac OS Extended volumes on the drive. 
Windows is installed to UEFI boot.