Search results
Results from the WOW.Com Content Network
File size is a measure of how much data a computer file contains or how much storage space it is allocated. Typically, file size is expressed in units based on byte. A large value is often expressed with a metric prefix (as in megabyte and gigabyte) or a binary prefix (as in mebibyte and gibibyte). [1]
For example, the first commercial hard drive, IBM's RAMAC in 1957, supplied 3.75 MB for $34,500, or $9,200 per megabyte. In 1989, a 40 MB hard drive cost $1200, or $30/MB. And in 2018, 4 Tb drives sold for $75, or 1.9¢/GB, an improvement of 1.5 million since 1989 and 520 million since the RAMAC.
Using the 24-bit memory addressing capabilities of the 286 CPU architecture, a total address space of 16 MB was accessible. Memory above the 1 MB limit was called extended memory. However the area between 640 KB and 1 MB was reserved for hardware addressing in IBM PC compatibles.
Thus, for example, the capacity of a "10 MB" (decimal "M") disk drive could be reported as "9.56 MB", and that of a "300 GB" drive as "279.4 GB". Some operating systems, such as Mac OS X , [ 33 ] Ubuntu , [ 34 ] and Debian , [ 35 ] have been updated to use "MB" and "GB" to denote decimal prefixes when displaying disk drive capacities and file ...
In this convention, one thousand and twenty-four megabytes (1024 MB) is equal to one gigabyte (1 GB), where 1 GB is 1024 3 bytes (i.e., 1 GiB). Mixed 1 MB = 1 024 000 bytes (= 1000×1024 B) is the definition used to describe the formatted capacity of the 1.44 MB 3.5-inch HD floppy disk , which actually has a capacity of 1 474 560 bytes .
Thus, a representation that compresses the storage size of a file from 10 MB to 2 MB yields a space saving of 1 - 2/10 = 0.8, often notated as a percentage, 80%. For signals of indefinite size, such as streaming audio and video, the compression ratio is defined in terms of uncompressed and compressed data rates instead of data sizes:
Very often, when referring to the word size of a modern computer, one is also describing the size of address space on that computer. For instance, a computer said to be "32-bit" also usually allows 32-bit memory addresses; a byte-addressable 32-bit computer can address 2 32 = 4,294,967,296 bytes of memory, or 4 gibibytes (GiB). This allows one ...
Logical block addressing (LBA) is a common scheme used for specifying the location of blocks of data stored on computer storage devices, generally secondary storage systems such as hard disk drives. LBA is a particularly simple linear addressing scheme; blocks are located by an integer index, with the first block being LBA 0, the second LBA 1 ...