Performance Tuning

LUG Helper

We have a helper script which can help you manage and optimize Star Citizen on Linux. It can check/set recommended settings such as vm.max_map_count and the system's open file descriptors limit, manage Lutris runners and DXVK versions, delete your Star Citizen USER directory while preserving keybinds, and delete shaders or dxvk cache for troubleshooting purposes. It can be downloaded from:

https://github.com/starcitizen-lug/lug-helper

Nvidia Cache

By default Nvidia has a combined cache for all games. As the cache fills up from other games, Star Citizen's shaders may get deleted leading to poor FPS. We recommend giving SC its own persistent cache by adding the following environment variables:

__GL_SHADER_DISK_CACHE=true
__GL_SHADER_DISK_CACHE_PATH="/path/you/want/for/your/cache"  (example: /home/games/star-citizen/nvidiacache)
__GL_SHADER_DISK_CACHE_SKIP_CLEANUP=true

If you use Lutris, these environment variables can be added here:

Right click the game->Configure->System options->Environment variables

Mesa (AMD/Intel) Shader Cache

Mesa can be given its own persistent shader cache by adding the following environmental variables:

MESA_SHADER_CACHE_DIR="/path/you/want/for/your/cache"  (example: /home/games/star-citizen/amdcache)
MESA_SHADER_CACHE_MAX_SIZE=10G

If you use Lutris, these environment variables can be added here:

Right click the game->Configure->System options->Environment variables

Game Settings

The following game settings can help improve framerates:

• Set Quality to High. Lower settings are not recommended as it will tax your CPU more. Set to Very High to offload more work from your CPU to your GPU.
• Set Planet Volumetric Clouds to Medium
• Set Scattered Object Distance to Low
• Set Motion Blur to Off
• Set Sharpening to 100

Feral GameMode

Gamemode can help improve performance by applying OS-level performance tweaks as the game is launched. Search for gamemode in your Distro's repos. Once installed, Lutris has a toggle for Enable Feral GameMode under System options. It defaults to ON if it detects gamemode is installed.

Fsync

An fsync-enabled Kernel can help improve smoothness while shaders are being compiled in the game. Enable fsync in Lutris under Runner Options.

Zram & Swap

We currently recommend a combined 40GB RAM + swap to avoid Out Of Memory crashes while playing Star Citizen. Systems with less than 40GB RAM will need additional swap or zram configured.

Zram stores swap in RAM using on-the-fly compression which can improve game performance when memory utilization gets high. In our experience, this tends to provide better performance in Star Citizen than zswap.

• For systems with 16GB RAM, we recommend all 16GB configured for zram with at least an 8GB swap file.
• For systems with 32GB RAM, we recommend configuring all 32GB for zram with at least a couple extra GB in a swap file.

Tip

When using zram, zswap needs to be disabled.
See the Arch Wiki for zram setup instructions that should work for most distros.
Also see the Arch Wiki for swap file creation instructions.

If you prefer not to use zram, a swap file will need to be configured. Btrfs users please follow the Btrfs instructions. We recommend configuring at least a combined 40GB RAM + swap:

• For 16GB RAM: 24GB swap
• For 32GB RAM: 8GB swap

Important

More swap should be configured if you intend to run background applications while playing the game.

Picom/Compton Compositors

If you use the Picom or Compton compositor, it may cause a laggy experience despite having high framerates. We recommend disabling the compositor. In Lutris:

1. Right click the game->Configure->System options. Turn on the option to Disable desktop effects.
2. If this doesn't work, it may be due to a bug in Lutris. You can use the Pre-launch and Post-exit script fields in the System options tab to run a script that kills picom/compton and then restarts it.

Steam Deck

• We recommend a 32gb+ swap file for the Steam Deck. Create it under /home instead of / to protect it from being wiped out by SteamOS updates.
• max allocation of ram to vram
• install lutris in desktop mode

Changing CPU scaling behavior via the Linux kernel and System Management BIOS

To achieve a more stable framerate in Star Citizen, ideally you will want a stable CPU frequency. There are several schedulers provided by the Linux kernel. Start with the Performance scheduler to hint that the CPU should always run at the maximum frequency before trying the demand-based schedulers.

We have discovered that Dell laptops with Intel CPUs (and possibly other mobile hardware configurations) may have other factors that influence CPU frequency scaling:

• In situations where one of these laptops is either thermal-limited or power-limited, the CPU and GPU will set the maximum frequency and then fall to a low frequency (ie. 800 MHz) when it hits the limit.
• You can try to configure these settings in the BIOS or via SMBIOS. On Ubuntu distributions, this utility is provided by the smbios-utils package.

Solution for affected laptops:

If changing the kernel scheduler between Performance and the various demand-based schedulers doesn't affect CPU frequency scaling for your laptop, try setting the SMBIOS thermal mode to cool-bottom. This mode behaves similarly to the Conservative kernel governor, gradually incrementing/decrementing the CPU frequency to stabilize the framerate.

• Using the SMBIOS utility on Ubuntu, the command is sudo smbios-thermal-ctl --set-thermal-mode=cool-bottom

Increased performance for CPUs with multiple dies

Affected CPU generations

• Amd Threadripper

Steps

1. Verify you have a CPU with multiple dies by running lstopo. If the results appear similar to the first image below, you can proceed:
   

   If, on the other hand, your CPU is like this image where the dies are not shown, this will not improve your performace:
   

2. Modify the following environment variable to match your system:

   WINE_CPU_TOPOLOGY=Number_of_Threads:List_of_threads_indexes
   

   The Number_of_threads is the number of threads you want to run Star Citizen with.
   The List_of_thread_indexes can be determined by looking at the lstopo output.
   You can see the threads highlighted in the image below:
   

   As an example, the CPU shown below would end up with the arguments

   WINE_CPU_TOPOLOGY=16:0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
   

   

3. Run the game with the modified environment variable. If using Lutris, add the modified environment variable as shown in the image below: Right click the game->Configure->System options->Environment variables