Should I Buy One 4TB SSD or Two 2TB SSDs?

Two drives can still be useful if you prefer separating the operating system and applications from games or project files. It can make reinstalling Windows or moving a game library easier, but it usually won’t provide a noticeable speed increase with modern NVMe SSDs. Check your motherboard manual for the exact M.2 slot bandwidth, since some slots can share lanes with other devices, although using one GPU and a couple of drives is generally fine.

A practical setup would be one 4TB NVMe SSD for active work, games, and media, with a larger HDD or another backup device for files you want to preserve. If you like having a dedicated system drive, two 2TB SSDs are also perfectly reasonable, but choose based on organization and upgrade plans rather than expecting a major performance or reliability advantage.

For most people, one larger NVMe drive is the simplest option. It leaves an M.2 slot available for a future upgrade and avoids having to manage separate boot, game, and data drives. A single drive should also perform perfectly well for gaming, coding, and normal editing workloads.

Don’t treat two SSDs as a backup. If one fails, you may lose less data than with one drive, but anything stored on the failed drive is still gone. Back up important files separately, preferably to an HDD or NAS for affordable capacity, plus cloud or off-site storage for anything you really cannot replace. SSDs can fail too, even if they are generally faster and quieter than hard drives.