An exabyte of digital storage is slightly more than one billion gigabytes. Though most home computer users might never need billion-gigabyte hard disks, total worldwide digital storage already exceeds 800 exabytes. This document defines digital-storage measurements, our expanding digital universe, and the growing digital storage requirements of business and science.
Comparing Digital Storage Measurements
Trained to use decimal numbers, people usually approximate digital-storage capacities as the base 1,000 raised to various exponents, such as 1,000^2 = 1,000,000 bytes as a megabyte, and 1,000^3 = 1,000,000,000 bytes as a gigabyte. However, digital storage media of all sizes are organized according to binary values. Therefore, as follows, precise measurements of digital storage capacities are the base 1,024 raised to various exponents:
* One kilobyte is precisely 1,024^1 bytes = 1,024 bytes.
* One megabyte is precisely 1,024^2 bytes = 1,024 X 1,024 bytes = 1,048,576 bytes.
* One gigabyte is precisely 1,024^3 bytes = 1,024 X 1,024 X 1,024 bytes = 1,073,741,824 bytes.
* One terabyte precisely 1,024^4 bytes = 1,099,511,627,776 bytes.
* One petabyte is precisely 1,024^5 bytes = 1,125,899,906,842,624 bytes.
* One exabyte is precisely 1,024^6 bytes = 1,152,921,504,606,846,976 bytes.
* One zettabyte is precisely 1,024^7 bytes = 1,180,591,620,717,411,303,424 bytes.
Our Expanding Digital Universe
The International Data Corporation (IDC) defines the total digital data we have created worldwide during all human history as our digital universe. According to Data Center Knowledge, the IDC reports that our digital universe grew to almost 800 exabytes in 2009. Moreover, despite current global economic problems, the IDC expects our digital universe to grow to approximately 1.2 zettabytes (1,200 exabytes) in 2010.
Increasing Digital Storage for Home and Business
For home computers, we currently measure digital storage capacities in gigabytes, but are beginning to use terabytes. Many advanced computer systems and data centers currently use petabytes, but will soon need exabytes. Future data centers will almost certainly need zettabytes. While adding greater digital storage capacities, we must develop better data-processing hardware and software. For more information, please see: Fred Beringer: Future of Data and Predictive Analytics.
Increasing Digital Storage for Science
Scientists will soon require many exabytes of digital storage. For example, within 20 years, international astronomers will share the Square Kilometer Array, a new radio telescope that will collect exabytes of data. Astronomers are also developing virtual observatories, each of which will integrate exabytes of data from multiple telescopes, both on land and in space. Therefore, astronomers will need not only newer, faster computers to process these data, but also multiple exabytes of magnetic and/or optical media in which to store them. For more information, please see: California Institute of Technology: Universe of Astronomical Data.
Hopefully, this document has introduced you to some new terms, and helped you ponder the possible future of digital storage.