SteamOS 3 ¶

Table of Contents

SteamOS 3

Game Mode is the name of the default mode that Steam OS and the Steam Deck boots into. It is limited to only accessing games from the Steam library. This is not to be confused with Feral Interactive’s GameMode.

Supported Controllers ¶

These are controllers that are officially supported on SteamOS [4][5]:

Nintendo Joy-Con controllers
Nintendo Online classic controllers
PlayStation Dualshock 4
PlayStation Dualsense 5
Steam Controller
Xbox 360 controller
Xbox One controller
Xbox Series controller
DirectInput controllers
Generic XInput controllers

Desktop Mode ¶

Enable Desktop Mode ¶

By default, the Steam Deck only works in Game Mode. Developer Mode must be enabled to access Desktop Mode.

STEAM > Settings > System > SYSTEM SETTINGS > Enable Developer Mode: Yes

Default User Account ¶

By default, on the Steam Deck, the user and group deck (UID and GID 1000) is used. It is also part of the wheel group (GID 998) which provides it access to running commands as the root user with the sudo command.

There is no password by default. For running sudo commands, a password needs to be set.

GUI: System Settings > Personalization > Users > Your Account > Steam Deck User > Change Password
CLI:
```
$ passwd
```

Transfer Files with SFTP ¶

SFTP provides FTP over the SSH protocol. This can be used to move files to and from the Steam Deck.

Ensure that a password has been set for the deck user.
```
$ passwd
```
Enable the SSH daemon.
```
$ sudo systemctl enable --now sshd
```
Find the current IP address.
```
$ ip address
```
Use an SFTP client, such as FileZilla, from a different computer to connect to the Steam Deck.
- Host: <STEAM_DECK_IP_ADDRESS>
- Username: deck
- Port: 22

[1]

Increase Swap Size and VRAM ¶

By default, SteamOS uses a 1 GiB swapfile at /home/swapfile. Combined with the Steam Deck’s 16 GB of RAM, it provides a total of 17 GB of temporary storage that is shared between the CPU and iGPU. The swappiness is set to 100% so Linux will always be writing as much temporary storage to the swap file as possible.

$ cat /proc/swaps
Filename                             Type            Size            Used            Priority
/home/swapfile                          file         1048572         0               -2
$ sysctl --values vm.swappiness
100

It is recommended to increase the swap size to 16 GB on Steam Deck models that have more than 64 GB of storage. The 256 GB and 512 GB models have more storage and are faster NVMe drives. An increased amount of swap frees up RAM for use as VRAM. Decreasing the swappiness down to 1% will increase the lifespan of the internal storage. These changes can result in up to 24% more FPS in more demanding games.

CryoUtilities provides a streamlined way to increase the swap file size, decrease swappiness, and make other performance improvements.

$ cd ~/Downloads/
$ wget https://raw.githubusercontent.com/CryoByte33/steam-deck-utilities/main/InstallCryoUtilities.desktop
$ chmod +x InstallCryoUtilities.desktop

Select the “InstallCryoUtilities.desktop” shortcut to install the tools. Then select the new “CryoUtilities” desktop shortcut. This will have prompts to walk through setting up the 16 GB swap file and 1% swappiness level.

$ cat /proc/swaps
Filename                             Type            Size            Used            Priority
/home/swapfile                          file         16777212        0               -2
$ sysctl --values vm.swappiness
1

VRAM is the amount of system RAM that is used for the iGPU instead of the CPU. The Steam Deck can use up to 8 GB of RAM as VRAM. In the BIOS, it is possible to set the minimum amount of VRAM the iGPU can use to 4 GB (up from 1 GB).

Press the “volume up” and “power” buttons to enter the BIOS > Setup Utility > Advanced > UMA Frame buffer Size: 4G > Exit > Exit Saving Changes

Verify that the changes have been made:

$ glxinfo | grep -i "dedicated video memory:"
   Dedicated video memory: 4096 MB

[2][3]

Enable TPM ¶

The original Steam Deck BIOS had TPM support disabled. It was eventually enabled to allow Windows 11 to be installed onto the device. [6] However, SteamOS never re-enabled TPM support. Here is how to re-enable it [7]:

Edit the GRUB configuration file: /etc/default/grub.
Go to the GRUB_CMDLINE_LINUX_DEFAULT= line and remove module_blacklist=tpm.
Update the GRUB boot menu.
```
$ sudo update-grub
```
Reboot.
Verify that TPM is working by seeing if the Linux device files exist.
```
$ find /dev -name "tmp*"
/dev/tpmrm0
/dev/tpm0
```

Disable SteamOS Updates ¶

SteamOS operating system updates can only be disabled from the Desktop Mode.

Disable updates:

$ sudo steamos-readonly disable
$ sudo chmod -x /usr/bin/steamos-atomupd-client
$ sudo chmod -x /usr/bin/steamos-atomupd-mkmanifest
$ sudo chmod -x /usr/bin/steamos-update
$ sudo chmod -x /usr/bin/steamos-update-os
$ sudo steamos-readonly enable

Re-enable updates:

$ sudo steamos-readonly disable
$ sudo chmod +x /usr/bin/steamos-atomupd-client
$ sudo chmod +x /usr/bin/steamos-atomupd-mkmanifest
$ sudo chmod +x /usr/bin/steamos-update
$ sudo chmod +x /usr/bin/steamos-update-os
$ sudo steamos-readonly enable

History ¶

Bibliography ¶

“Transferring files from PC to Steam Deck with FileZilla FTP.” GamingOnLinux. September 29, 2022. Accessed November 3, 2022. https://www.gamingonlinux.com/2022/09/transferring-files-from-pc-to-steam-deck-with-ftp/
“OLD | EASY Performance Boosts for Steam Deck!” YouTube CryoByte33. October 14, 2022. Accessed November 20, 2022. https://www.youtube.com/watch?v=3iivwka513Y
“EASY & SAFE Health & Performance Boosts | Steam Deck.” YouTube CryoByte33. November 4, 2022. Accessed November 20, 2022. https://www.youtube.com/watch?v=od9_a1QQQns
“How to use an external controller on Steam Deck.” PCGamesN. June, 2022. Accessed February 16, 2023. https://www.pcgamesn.com/steam-deck/external-controller
“Steam Client Beta - August 4.” Steam Community. August 4, 2022. Accessed February 16, 2023. https://steamcommunity.com/groups/SteamClientBeta/announcements/detail/3387288790681635164
“Steam Deck adds Windows 11 support and BIOS fixes with beta update.” XDA Portal & Forums. April 1, 2022. Accessed February 17, 2023. https://www.xda-developers.com/steam-deck-windows-11-bios-beta/
“How to use the TPM on Steam Deck in SteamOS.” jiankun.lu. November 14, 2022. Accessed February 17, 2023. https://jiankun.lu/blog/how-to-use-the-tpm-on-steam-deck-in-steamos.html