10 Gigabytes per Second in Perspective: A Byte-Size Wonder

Digitized archive of the Library of Congress

(This is the second in a four-part post that puts 10GB in perspective. In the first part, we described what a hypothetical movie-binging robot might be able to do with a 10GB/s SSD. In this section, we hope to provide simple definitions for standard units of measurements used in storage and computer technologies.)

All data in a modern computer system is quantified in terms of its number of bits and/or bytes.

Bits, abbreviated with a lowercase b, are the basic building blocks of information in the digital age. The word bit is short for binary digit and is the smallest unit of data with computer systems today. As a binary unit, a bit can only have one of two values: 0 or 1, true or false, on or off, charge or no charge, etc.

Computers might be able to test or manipulate these individual bits, but when it comes to locating data or executing instructions, they can really only do so on groups of bits called bytes. Bytes, abbreviated with an uppercase B, make up the smallest addressable unit of memory used to encode a single character of text in a computer architecture.

Today, the 8-bit byte is the most widely accepted convention. So, if you feel the need to convert between bits to bytes, you simply divide the number of bits by 8 to get the number of bytes; multiply the number of bytes by 8 to get the number of bits.

Overbytes

The vast amounts data being stored, transmitted, saved and deleted every moment of every day in today’s information society can be staggering for non-robots to wrap their heads around. Like the number of stars in the Carl Sagan cosmos, “billions and billions” of bytes are stored in even the most humble thumb drives that people carry in their jeans pockets. Because of the extremely large numbers involved, bits and bytes are seldom mentioned without special prefixes to help normal people understand them.

Some of the most common of these prefixes, their abbreviations and their meanings are listed in the following table:

Prefix Standard Abbreviation Meaning
kilo K Thousand
mega M Million
giga G Billion
tera T Trillion
peta P Quadrillion

When used with basic units of measurement these prefixes serve as multipliers. So, if the basic unit of measurement is a bit, then 1Gb would be 1 billion bits; if the basic unit of measurement is a byte, then 10GB would be 10 billion bytes.

Examples of other prefix uses follow:

  • 2400Kb = 2,400,000 bits
  • 512KB = 512,000 bytes
  • 1.04MB = 1,040,000 bytes
  • 10GB = 10,000,000,000 bytes

Without adequate points of reference, none of this information would mean much. Numbers in themselves are abstract. To give you an idea of what these numbers can be used for, the following table lists some real-world items with which you may be familiar as well their typical data capacities.

Description Typical Size
e-book 1MB-5MB
MP3 3.5MB
CD-ROM 750MB
DVD Movie 4GB
1080p (HD) Movie 8GB-15GB
Blu-Ray Movie 10GB-25GB
4K Movie 100+ GB
Library of Congress digitized archive (2009) 74TB

So far, defining the two basic units of measurement for data has been pretty straightforward. But, of course, there are devils in the details. The next section will cover some of the finer points you might need to be aware of when talking about bits and bytes.

2017-12-06T15:25:20+00:00

About the Author:

Kent Smith