Steam Deck OS occupies 10GB, leaving about 50GB free for games in the base version

Several people expressed concerns over the size of Steam Deck's operating system, which is based on the Linux operating system. This is because the number of games that can be installed on the device is directly proportional to the amount of storage that the device has. 

Fortunately, some facts were revealed that give us a sense of how much space SteamOS 3 will take up on the console's SSD, allowing players who belonged to this category to breathe a sigh of relief. This information was shared by user Madjoki , who posted in the MetaCouncil forum an image with some notes of the version 20211120.2 of SteamOS 3. According to these notes, this version of the operating system reduces the size used from 24GB to 10GB, which means that about 50GB will be left free for the storage of games and applications in the standard model, which is not bad at all. Also, considering that Valve managed to reduce the size of SteamOS 3 considerably, there is a possibility that the company could continue to reduce it even more and take up even less space when the Steam Deck is released.

It will, however, be required to create additional storage space.
Since there are some games that will not load even if we do not have any other games installed on the Steam Deck's standard version, which has just 64GB of RAM, customers are practically forced to purchase additional storage space. The Witcher 3, for example, which we previously observed operating on the Deck, may take up around 45GB after installation, leaving us with no capacity left for another game. Having a single gaming console does not make much sense in this situation. Finally, Valve wants to make sure that all of the games work properly on the Steam Deck, so they have been testing the whole catalog of titles available on the shop. In the event that consumers must choose which games to install on their limited storage space, they may at least be confident that the games will operate properly.