Computer System: Memory

Computer System: Memory

Types of Memory

  • The term memory in computing generally refers to the device or medium data is stored on.
  • There are several types of memory in a computer system including RAM, ROM, and storage.

RAM (Random Access Memory)

  • RAM is the main memory in a computer, where program instructions and data are loaded to be processed by the CPU.
  • It is called ‘random access’ because any memory cell can be accessed directly if the row and column is known.
  • RAM is volatile, meaning all information stored in it is lost once the computer is turned off.
  • The more RAM a computer has, the more processes it can handle simultaneously, increasing performance.

ROM (Read Only Memory)

  • ROM is a type of memory that stores instructions needed to start up the computer. This is known as the BIOS (Basic Input/Output System).
  • Unlike RAM, ROM is non-volatile, meaning the information is not lost when the computer is turned off.
  • Data in ROM is written during manufacturing and cannot be modified or deleted by normal computer operations.

Virtual Memory

  • Virtual memory is a section of volatile memory created temporarily on the storage drive. It is created when a computer is running many processes at once and RAM is running low.
  • Virtual memory is slower than RAM, so the system may become sluggish if it relies too much on virtual memory.

Cache Memory

  • Cache memory is a small amount of high-speed RAM that stores frequently used data and instructions.
  • Cache memory is quicker to access than using regular RAM, so it enhances the system’s performance.
  • The CPU checks for data in the cache memory before searching in the slower main RAM.

Storage

  • Storage refers to permanent, non-volatile memory like hard drives and SSDs (solid-state drives) which store data and software.
  • Compared to RAM, storage is slower to read from and write to.
  • However, storage has much higher capacity and retains information even when power is not supplied.

Memory Management

  • Memory management is the process through which a computer handles and allocates memory.
  • It involves tracking each byte in a system’s memory, and maintaining and recovering the memory.