Exbibyte to Pebibyte

EB (exabyte) = 10¹⁸ bytes (SI decimal). EiB (exbibyte) = 2⁶⁰ bytes = 1,152,921,504,606,846,976 bytes (IEC binary). EiB is 15.29% larger. This is the largest practically significant SI vs IEC discrepancy: per exbibyte, the binary value exceeds the decimal value by approximately 152,921,504,606,846,976 bytes — about 152.9 petabytes.

One exbibyte (EiB) ≈ 1.153 × 10¹⁸ bytes = 1,073,741,824 GiB = 1,048,576 TiB. In practical terms: enough to store approximately 230 billion JPEG photos at 5 MB each, or 288,230,376 copies of a 4 GB HD movie, or the entire text content of the English internet many thousands of times over.

In theory, yes — and with astonishing density. DNA can encode about 215 PiB per gram of material, meaning a single EiB could fit in roughly 4.7 grams of synthetic DNA. Researchers at Microsoft and the University of Washington have demonstrated writing and reading megabytes of data in DNA strands. The challenges are speed and cost: current DNA synthesis writes about 400 bytes per second and costs around $3,500 per megabyte. At that rate, writing 1 EiB would take billions of years and cost more than global GDP. However, enzymatic synthesis breakthroughs could reduce costs by 6–8 orders of magnitude within decades.

Storing 1 EiB on modern HDDs would require roughly 57,000 drives of 20 TB each, consuming about 400–500 kW of power just for the drives — plus 200–300 kW for cooling, networking, and overhead. That totals roughly 6 GWh per year, equivalent to powering about 550 US homes. At typical US grid carbon intensity, this produces around 2,500 tonnes of CO₂ annually. Hyperscale operators reduce this via renewable energy and immersion cooling, but the fundamental physics of spinning magnetic platters or maintaining NAND charge states sets a floor on energy consumption that no software optimisation can eliminate.

After exbibyte (EiB, 2⁶⁰ bytes) come: zebibyte (ZiB, 2⁷⁰ bytes) and yobibyte (YiB, 2⁸⁰ bytes), as defined in IEC 80000-13. These are recognized standard units but have no current practical applications. The entire global internet's estimated stored data (hundreds of EB) is still in the low hundreds of EiB range — well short of one ZiB.

PB (petabyte) = 10¹⁵ bytes = 1,000,000,000,000,000 bytes (SI decimal). PiB (pebibyte) = 2⁵⁰ bytes = 1,125,899,906,842,624 bytes (IEC binary). PiB is 12.59% larger. For a data center purchasing 100 PiB of raw storage, the SI vs IEC confusion would represent approximately 12.59 PB of missing or unexpected capacity.

Cloud providers (AWS, Azure, GCP) operate at exabyte scale but provision and bill individual customers at PiB scale for enterprise storage. Scientific computing facilities like CERN, the Square Kilometer Array telescope project, and US national laboratories store tens to hundreds of PiB. Large video platforms (Netflix, YouTube) store hundreds of PiB of encoded video content.

Using 20 TB drives (a 2024 high-density consumer drive): 1 PiB = 1,125,899,906,842,624 bytes ÷ 20,000,000,000,000 bytes/drive ≈ 56.3 drives. So roughly 57 × 20 TB drives to fill 1 PiB. In a data center using 60-drive storage shelves, one shelf of 60 × 20 TB drives provides about 1.07 PiB of raw capacity.

Magnetic tape (LTO technology) remains the dominant medium for cold storage at PiB scale due to economics and durability. An LTO-9 cartridge holds 18 TB (uncompressed) and costs roughly $100 — about $5.50 per TB, versus $15–20 per TB for HDDs. Tape also consumes zero power when idle, unlike spinning disks. The IBM TS4500 tape library can hold over 40 PiB in a single rack. Major users include CERN, national archives, and film studios — Netflix stores its master copies on tape. Tape's main downside is sequential access: retrieving a specific file can take minutes versus milliseconds for disk.

CERN's Worldwide LHC Computing Grid stores approximately 300–400 PB (petabytes, decimal) of data across distributed sites, with the main Tier-0 facility at CERN holding about 100 PB on disk and 200 PB on tape. The LHC generates roughly 15 PB of data per year from collision events. Future upgrades (High-Luminosity LHC) are projected to increase this to 50–100 PB per year.