Storage

Storage

1. Primary Memory

   • ROM
     • Read Only Memory, data that is vital to the operation of the computer e.g. BIOS. This cannot be altered, deleted or tampered with. Unfortunately it cannot be upgraded or updated
   • RAM
     • Random Access Memory, Stores the programs that are being used by the computer (including the OS). RAM is volatile memory, all data stored onto it is lost when the computer is turned off

2. Secondary Storage

   • Optical
     • It is relatively cheap, reliable and can be mistreated with no ill effects as long as the surface of the disc is protected. Data is read by a laser. Examples are CDs, DVDs and Blu-Ray discs. Most Optical media is read-only, very rarely rewritten e.g. CD-RWs
   • Magnetic
     • There are two types of Magnetic media - tape and disks. Tape is mostly used for archiving, as it takes a long time to "seek" between two sections of tape. Hard Disks are mainly used for long term data storage, speed is important.They are read using a "head" which skims the surface of several "platters", or disks. They are faster than tape and optical but slower than SSD.
   • Solid State
     • Divided into tow categories - "slow" storage (such as a flash drive), and "fast" storage (such as an SSD). All solid state storage is very good at dealing with small files, as no movement is required to "find" (seek) files. SSD's are fast enough to replace traditional hard drives, 4 to 5 times faster than a spinning hard drives. A flash drive is 20 times slower than hard drives, even though they can seek faster.