How much storage should I dedicate to a Linux system drive?

My Linux root filesystem is under 50GB even with a lot of installed software. The home directory is larger because of caches, configuration files, downloads, and application data, but those are still manageable. Linux also lets you relocate directories using mounts or symbolic links, so applications don’t need to know which physical drive stores their data.

For a typical desktop, 512GB is already plenty. You could put the system root on roughly 100–200GB and use the rest for your home directory, while keeping games, media, backups, and project files on the other drives. A 2TB NVMe is mainly worthwhile if you want to keep games or large working files on the fast drive.

Remember that the boot partition and the main root filesystem are different things. The boot partition only contains boot files and several kernels, so a few gigabytes is normally plenty; around 5GB leaves comfortable room. The root filesystem needs more, especially if you install lots of software, but 50–100GB is a reasonable starting point.

Linux itself generally doesn’t need much space. A 120–256GB drive is enough for the OS and a substantial amount of software if your large files are stored elsewhere. Application settings and caches usually live under your home directory, which can be placed on a separate partition or drive.

For photo and video work, the important question is where each program stores its catalogs, previews, cache, and scratch files. Those can often be configured to use another drive. I’d use the 512GB NVMe for Linux and applications, then keep the media library and large caches on the other SSDs unless you specifically need the speed of the 2TB drive.