A 2TB SSD (Solid-State Drive) has an actual usable capacity slightly less than 2 terabytes. This discrepancy is due to differences in how storage capacity is measured by manufacturers and how it’s reported by the operating system.
Manufacturer’s Capacity: Manufacturers typically use decimal counting and define 1 terabyte (TB) as 1,000,000,000,000 bytes. Therefore, a 2TB SSD is calculated as 2,000,000,000,000 bytes using this standard.
Computer Science Standard: In computer science, storage capacity is often represented using powers of 2, where 1 terabyte is equal to 2^40 bytes, which is approximately 1,099,511,627,776 bytes.
As a result of these different standards, the actual usable capacity of a 2TB SSD is approximately 1.81 to 1.86 terabytes when viewed in the computer science standard. This discrepancy is entirely normal and is not unique to SSDs; it applies to all storage devices. It occurs because of the way storage capacity is calculated and allocated for system-related tasks.
In practical terms, you should expect your 2TB SSD to have slightly less than 2TB of usable storage space for your data and applications once the operating system and file system overhead are taken into account.
