Unit of Measurements

Unit of Measurements 

Storage measurements

The basic unit used in computer data storage is called a bit (binary digit). Computers use these little bits, which are composed of ones and zeros, to do things and talk to other computers. All your files, for instance, are kept in the computer as binary files and translated into words and pictures by the software (which is also ones and zeros). This two number system, is called a “binary number system” since it has only two numbers in it. The decimal number system in contrast has ten unique digits, zero through nine. 

Computer Storage units 

Bit BIT 0 or 1 

Kilobyte KB 1024 bytes 

Megabyte MB 1024 kilobytes 

Gigabyte GB 1024 megabytes

Terabyte TB 1024 gigabytes

 Size example 

• 1 bit- answer to an yes/no question 

• 1 byte- a number from 0 to 255.

• 90 bytes-enough to store a typical line of text from a book.

• 4 KB- about one page of text.

• 120 KB- the text of a typical pocket book. 

• 3 MB- a three minute song (128k bitrate)

• 650-900 MB- an CD-ROM

• 1 GB-114 minutes of uncompressed CD-quality audio at 1.4 Mbit/s 

• 8-16 GB- size of a normal flash drive

Speed measurement

The speed of Central Processing Unit (CPU) is measured by Hertz (Hz), Which represent a CPU cycle. The speed of CPU is known as Computer Speed. 

CPU SPEED MEASURES 

1 hertz or Hz 1 cycle per second 
1 MHz 1 million cycles per second or 1000 Hz 
1 GHz 1 billion cycles per second or 1000 MHz