Dual Boot Steam Deck SD card

[Scarlet Symphony]

So I have set up my Steam Deck to dual boot SteamOS and Windows 10.

I recently bought a 512 GB sd card to store my games. I formated it in SteamOS, works fine.

Then when I went to launch Windows, it asked me to format it again, sure, havent downloaded anything yet.

Now my sd card currently has Genshin on it, but when I rebooted into SteamOS, it is telling me to format it again. But the sd card shows up in desktop mode.

Can I not use the same sd card for both SteamOS and Windows?

[Jâbbérwôkkï]

Steam Deck & Windows use different file system structures (SD - ex-fat, Windows -NTFS). They are not compatible file systems. Your best bet if you want to dual boot them is to keep Steam Deck games stored on the deck's internal drive, with Windows & its games on the sd-card. Otherwise, if you were to try to put Windows in a Partition on the Deck's internal drive, every time Steam Os had an update it would wipe all your work of installing Windows & anything installed on the Windows partition.

[IscariotPaladin]

First off Disclaimer: I have not dual boot my steam deck with windows so I may be wrong on some things but speaking computer tech wise. They are two different OS SteamOS is Lynx based so the files are not natively compatible with Win. Did you dual boot windows from the internal or install it to the SD card and your trying to dual boot it. If its the SD card you will need to shut down steam deck them boot it up while holding the power and volume up to bring up the boot menu this should allow you to select the windows sd card. If you have partitioned the internal drive with windows that way then the either you will need to partition the sd card as well to have steam os and windows if you want to use it for both keep in mind that any data on one side will not be able to be used on the other OS. On a side note how is dual booting windows on it does it run reasonably smooth and if so what way did you set up windows internally or microSD card? I've been thinking about it dual booting but lot of people just flat out say don't that's stupid or you'll mess up your hardware.

[Mahjik]

Originally posted by IscariotPaladin:

On a side note how is dual booting windows on it does it run reasonably smooth and if so what way did you set up windows internally or microSD card? I've been thinking about it dual booting but lot of people just flat out say don't that's stupid or you'll mess up your hardware.

Many people do it, it's fine. Most will do it on a SD card. You'll have some that say you'll destroy a SD with Windows on it (due the write activity) but nothing last forever in this world.

https://www.youtube.com/watch?v=rOCsMeKBGbo

[PopinFRESH]

Originally posted by Jâbbérwôkkï:

Steam Deck & Windows use different file system structures (SD - ex-fat, Windows -NTFS). They are not compatible file systems. Your best bet if you want to dual boot them is to keep Steam Deck games stored on the deck's internal drive, with Windows & its games on the sd-card. Otherwise, if you were to try to put Windows in a Partition on the Deck's internal drive, every time Steam Os had an update it would wipe all your work of installing Windows & anything installed on the Windows partition.

SteamOS doesn’t use ex-fat, it uses ext4 with casefolding. The rest of your point is accurate though.

@OP you can either modify SteamOS and manually install ntfs-progs to allow it to read NTFS file systems, or you can install the experimental support for btrfs on Windows and modify the SteamOS formatting script to use btrfs instead of ext4 with casefolding. Either option you might run into some odd issues or edge cases with some games running on the microSD card via proton but for the most part it should work.

Edit: The Phawx has a decent guide for doing this with btrfs

https://youtu.be/Pt-Y5DYy9mU