♥Secondary Storage♥

Disk Caching

A disk cache is a portion of a system memory used to cache reads and writes to the hard disk . It may be referred to as the most important type of cache on the PC , because of the greatest differential speed between the layers , that is the system RAM and the hard disk . Disk caching works under the same principle as Memory caching , but instead of using high-speed SRAM , a disk cache uses conventional main memory . The most recently accessed data from the disk , it first checks the disk cache to see if the data is there . Disk caching can dramatically improve the performance of applications because accessing a byte on a hard disk .

 

File Compression

File compression is commonly used when sending a file from one computer to another over a connection that has limited bandwidth . The compression basically makes the file smaller and , therefore the sending of the file is faster . The next step to compressing a single file is the combining of multiple files into a single compressed archive . Finally , combining multiple files into a single archive is to maintain the organization of those files once inside the archive .

File Decompression

Data decompression is the reverse , the decoding of compressed data to restore the original data .
Compression or decompression algorithnms look for redundancies in data , then minimize them using predetermined algorithms (methods) . There are different algorithms used to achieve different compression rates . Solid files are called 'archives' . They can hold more than one file . There is a tradeoff between higher density rates and compression or decompression time . Archive files can be manipulated utilities such as WinZip or IZArc .

Internet Hard Drive

The sole purpose of an Internet hard drive is to offer a means of accessing your computer files , for instance , pictures , document , music , video and many more from any computer , as long as that computer has access to the Internet . Similar to depositing money into your bank account and later withdrawing that same money from any ATM machines , an Internet hard drive will allow you to 'deposit' your computer files into a remote hard drive and then later access those very same files from any other computer .

Solid State Storage

Solid-state storage is a nonvolatile, removable storage medium that employs integrated circuits (ICs) rather than magnetic or optical media. It is the equivalent of large-capacity, nonvolatile memory .The main advantage of solid -state storage is the fact that it contains no mechanical parts . Everything is done electronically .The absence of moving parts may translate into longer operating life, provided the devices are reasonably cared for and are not exposed to electrostatic discharge.