Win 10 smallest partition size?

[FilmIndustryGuy]

I have the 128 gb MM18. I only use about 20gb due to external drives and iCloud. I read you can't run Win 10 off an external SSD. Id like to install windows and run all windows software off an external SSD. what's the smallest but practical size partition I should create for windows?

 

[Maccotto]

I chouce 130gb but 70gb are the minimal for win 10

 

[F-Train]

Apple addresses this here for Boot Camp: https://support.apple.com/en-us/HT201468

That page says:

Enough free disk space to create a Boot Camp disk partition* with a minimum size of 64GB. 128GB is recommended for the best experience.
​

I'd like to know myself where these numbers come from and their rationale. I am considering Boot Camp, but don't want to commit that much space to it. I'm only interested in it as gaming space, the games being kept on an external drive.

 

[F-Train]

Apparently Windows 10 needs about 20GB after updates, etc. Why does Apple say 64GB minimum, 128GB recommended? After the operating system, doesn't it depend on what applications one installs?

 

[Mikael H]

Apparently Windows 10 needs about 20GB after updates, etc. Why does Apple say 64GB minimum, 128GB recommended? After the operating system, doesn't it depend on what applications one installs?

Yes, but over time Windows also generates LOTS of cruft in the Windows directory. If it was for a permanent installation, I would not put Windows 10 on anything less than 50GB, and even that is tight (Since Windows 2012R2 I put my servers on 60 GB system volumes at work, and that's for machines where most data gets put on separate drives).

 

[Significant1]

Apparently Windows 10 needs about 20GB after updates, etc. Why does Apple say 64GB minimum, 128GB recommended? After the operating system, doesn't it depend on what applications one installs?

It also needs room for hibernation and swap file. Hibernation alone will be as big as your installed ram, if recall correctly. If you fiddle with settings you can disable hibernation and swap file. I also read yesterday, that they will new reserve extra 7GB for updates, which will be locked for other use.

Setting the size too small will be a pain and trying to increase it afterward a nightmare.

So if booting Windows from external drive is not possible, I would either look into a virtual machine solution (placing it on external drive) or use all 128GB for Windows and boot macOS from external drive

 

[F-Train]

booting Windows from external drive

That’s an interesting idea, if it works.