Pebibyte (PiB) - Unit Information & Conversion

Definition

A pebibyte (PiB) is a unit of digital information storage equal to 250 bytes, which is exactly 1,125,899,906,842,624 bytes (or 10245 bytes). It uses the binary prefix 'pebi-' established by the International Electrotechnical Commission (IEC). The pebibyte was created to provide an unambiguous measurement for byte multiples based on powers of 2, distinguishing it from the petabyte (PB), which is based on the decimal prefix 'peta-' (1015 or 1,000,000,000,000,000 bytes).

History

The prefix 'pebi-' (representing 250) was defined by the IEC in 1998 alongside other binary prefixes (kibi-, mebi-, gibi-, tebi-, exbi-). Before this standard, the SI prefix 'peta-' (P) was ambiguously used to represent both 1,000,000,000,000,000 (1015, as per its SI definition) and 1,125,899,906,842,624 (250) in computing contexts, especially for very large data volumes. This led to significant confusion when comparing storage capacities advertised by manufacturers (often using decimal prefixes) and those reported by operating systems or used in technical specifications (often using binary interpretations). The introduction of the pebibyte (PiB) aimed to resolve this ambiguity by providing a specific term for 250 bytes.

Common Uses

Pebibytes are used in contexts dealing with extremely large amounts of data storage where precision based on powers of 2 is necessary:

• Measuring the capacity of very large-scale storage systems, data centers, and cloud storage infrastructure.
• Reporting file system sizes and disk space usage by operating systems for extremely large volumes, especially where IEC standards are followed.
• High-performance computing (HPC), large dataset analysis (Big Data), scientific research, and simulations involving massive data storage requirements.
• Technical specifications for enterprise-level storage hardware and software where exact binary multiples are crucial.
• Archiving and backup systems handling petabyte-scale data.

Unit FAQs

How many bytes are in a pebibyte (PiB)?

There are exactly 250 bytes in 1 pebibyte (PiB). This equals 1,125,899,906,842,624 bytes.

How many tebibytes (TiB) are in a pebibyte (PiB)?

There are 1,024 tebibytes (TiB) in 1 pebibyte (PiB). This follows the binary prefix system where 1 PiB = 250 bytes and 1 TiB = 240 bytes, and 250 / 240 = 210 = 1,024.

What is the difference between a pebibyte (PiB) and a petabyte (PB)?

A pebibyte (PiB) represents 250 bytes (1,125,899,906,842,624 bytes), using the IEC binary prefix 'pebi-'. A petabyte (PB) typically represents 1015 bytes (1,000,000,000,000,000 bytes), using the SI decimal prefix 'peta-'. A pebibyte is approximately 12.6% larger than a petabyte (1 PiB ≈ 1.126 PB). Use PiB for precision in binary contexts (like large-scale OS reporting, HPC storage) and PB for decimal contexts (like marketing large storage systems) or when the specific definition is clarified.

What is the difference between a pebibyte (PiB) and a pebibit (Pib)?

A pebibyte (PiB) measures information in bytes, while a pebibit (Pib) measures information in bits. Assuming the standard 1 byte = 8 bits, 1 pebibyte (PiB) is equal to 8 pebibits (Pib). Both use the binary prefix 'pebi-' (250).

Why is PiB used less often than PB in marketing?

Marketing materials for large storage systems often use the decimal prefix (PB, EB) because it results in a larger-looking number for capacity compared to the binary prefix (PiB, EiB) for the same amount of physical storage. For example, 1015 bytes is marketed as 1 PB, while an OS might report a similar capacity using PiB (1 PB is approximately 0.888 PiB). Using decimal units allows manufacturers to advertise higher, rounder numbers, even though technical contexts often rely on binary measurements.