Question

Write a 1 to 2 page paper focused on data storage in various types of computer memory. Explain what types of memory are used, and the purpose of each type.

Answer 1

Data storage in various types of computer memory with an explanation on the types of memory that are used, and the purpose of each type:
Broadly categorized, data is stored in:
* Primary memory: It is called system memory. Primary memory is used for speedy access to data. It is located close to the CPU on the computer motherboard. It enables the CPU to read data from the primary memory.

* RAM: Random Access Memory is a primary memory. It is a volatile memory, as the data in it gets erased as soon as the computer is shut down. Data can be accessed in any random order. It is very fast. It supports both, read, and write operations. It is used by the CPU so data required for imminent processing is moved to RAM where it is accessed and modified instantly, so the CPU does not have to wait.

* Read-Only Memory (ROM) is a type of memory. ROM though is a non-volatile memory. Data can be only read from this type of computer memory, but cannot be written to it. It is used to store the bootstrap code. ROM, in turn, also comes in three types- PROM (Programmable Read-Only Memory), EPROM (Erasable Programmable Read-Only Memory), an Electrically Erasable Programmable Read-Only Memory (EEPROM).

* PROM EPROM: It is manufactured in an empty state and is later programmed using a PROM programmer or burner.

* EPROM: Data stored in it can be erased and reprogrammed.

* EEPROM: It is not strictly read-only. It can be erased and written to by the computer system it is installed in. it is used only to update program code, for example, firmware or BIOS code.

* SRAM (Static RAM): It is a type of RAM. It is faster than DRAM. It is used as a data cache within a CPU. Otherwise, it is used as a RAM in very high-end server systems. It is a volatile memory.

* DRAM (Dynamic RAM) are types of RAM. It is used to maintain data integrity. DRAM comes in Dual Data Rate DDR2, DDR3, and DDR4, with the latest one used for better performance and more energy efficiency.

* Secondary memory: It is called storage. It is physically located within a separate storage device. Secondary memory is used when there is no need for speedy access to data, but there is a need for the durability of data. This type of memory is non-volatile as it can store data and can be retained after the computer is restarted even when there was no power in the system earlier during the data was being stored in the memory. Examples of secondary memory are har disk, Solid State Drive (SSD), Compact Disks (CD) or Digital Versatile Disc (DVD), Floppy disk, and Magentic tap. It also includes flash memory.

* NAND flash memory: It is a flash memory found in USB memory sticks and Solid State Disk (SSD) drives. It is a type of EEPROM. It is a secondary memory.

Semi-volatile memory: This type of memory has some limited non-volatile duration after power has been shut down, however, data is ultimately lost. The purpose of using it to provide high performance, durability, etc., that are associated with volatile memories, and at the same time providing some benefits of a true non-volatile memory.

Virtual memory: It is a system in which the Operating System (OS) controls all physical memory. Whenever a program needs memory, it requests the OS and the OS decides in what physical location the program's code and data should be placed. The purpose is computer programmers to be free of the physical location the data would be stored or if the user's computer would have sufficient memory.

Protected memory: It is a system, in which, every program is given an area of memory to be used and the program is not permitted to go outside the specified range. The purpose of using protected memory is to enhance the reliability and security of a computer system.

Cache memory: It is also called the Central Processing Unit (CPU) cache. It is an extremely fast memory type. Its usage purpose is to act as a buffer between RAM and the CPU. It is used to hold frequently requested data and instructions for the CPU to access them immediately whenever needed. It is used for reducing the average time to access data from the Main memory