Valve's Steam Deck handheld automatically adjusts its minimum VRAM allocation in its native Linux-based OS, but you can manually set a value between 256MB to 4GB (of the 8GB available to its GPU) to help with gaming performance when using Windows 11 and even boost specific games in SteamOS. Here's how to increase the UMA Frame Buffer Size on your Steam Deck and experiment with games in each operating system.

You need to access the BIOS to adjust the Steam Deck's minimum VRAM allocation. You can access it from a cold boot sequence after a complete shutdown rather than quick-pressing the power button to enter sleep mode.

Hold the power button to show a 'Power' menu in 'Gaming Mode.'

Select 'Shutdown' and wait for your Steam Deck to switch off completely.

Hold the volume up (+) button and press the power button.

When the Steam Deck icon appears, release volume up (+)

Select 'Setup Utility' with the touchscreen or touchpad.

Navigate to 'Advanced' on the left-side submenu.

Select 'UMA Frame buffer Size' with the touchscreen or touchpad.

Set the 'UMA FB' size to your liking, from 256M (MB) to 4G (GB)