Talk:Steam Deck Q&A

detect fake microSD cards

To test microSD card for fake capacity on Linux:

Unmount the card.
Run full test (long, hours for 512GB):
sudo f3write /path/to/mount/point
Then sudo f3read /path/to/mount/point
Run quick test (minutes, destructive):
Confirm device (e.g., /dev/sdd) with lsblksudo f3probe --destructive --time-ops /dev/sdd

If quick test reports much less than labeled capacity or errors, card is fake.

PNY Premier-X 512GB A2 microSD

PNY Premier-X 512GB A2 microSD

mmblk0 - 464.38 GiB

Steam Deck handling of microSD Cards

Steam Deck handles one microSD card at a time via single slot; multiple means swapping user cards.

Launching game after replacing 128GB with 512GB card: New card inserted and formatted shows game as installed, but launch detects missing files and prompts verify integrity or download to new card. No prompt to insert old card; Steam Cloud syncs saves if enabled.

Typical user scenarios (2025-2026 reports):

• Multiple cards: Swap for themed libraries (e.g., AAA on one, indies on another). Inserted card games launch immediately; others prompt redownload on launch. Hotswap supported without shutdown.
• Upgrading size: Format new card in Game mode. Re-download small games; copy large ones via Desktop mode with USB hub/reader (old card in hub) or PC, then verify integrity.
• Transferring games: Manual copy steamapps/common folders to new card. Insert new; Steam verifies files, avoiding full redownload. Docked hub enables direct Deck transfer.