Different Types of Computer Memory

In a computer, all the programs are stored on a hard disk drive. Whenever you access any program, it is temporarily stored in the memory called RAM(random access memory) so that the CPU accesses this software quickly. Apart from RAM, different types of memory have their own roles in computing. Let’s explore different types of memory and their functionality.

Types of Computer Memory

1. Permanent memory
2. Temporary Memory

Permanent Memory

A memory that is not affected by the absence of electricity is a permanent memory and the data stored in it remains intact even if it is moved from one place to another. On a motherboard, it is present in an Integrated chip, also called ROM or BIOS. All the information about the motherboard, booting instructions, and functions are stored in BIOS at the time of manufacturing.

Permanent memory is of 4 types.

ROM (Read only memory). ROM, once manufactured cannot be changed. It is the static form of permanent memory. A commercially available movie or software on a CD-ROM is a good example of Read-Only-Memory. You cannot change the contents once the data has been written to it.

PROM (Programmable Read Only Memory). The hardware chip that can be programmed once is called PROM. Special Programmable kits are used to program the electronic chips. A common example is burning(writing data) on a CD-ROM or a DVD at home.

EPROM (Erasable Programmable Read Only Memory). This type of ROM has a small window on its top. If this window is exposed to UV light for a specific period of time, all the previous data is deleted. You can re-program it after the data has been completely removed.

EEPROM (Electrically Erasable Read Only Memory). This is the most used type of permanent memory. You can easily erase the data with a software program. BIOS on the motherboard is an example of EEPROM.

Temporary Memory

RAM (Random Access Memory) is another name for temporary memory. It is called temporary since all the data stored in RAM gets erased once the power is off. RAM is used to hold and execute the data or the instructions. Whenever we work on the computer, actually we are working on RAM and it’s only when we press the save button the data gets saved in permanent storage like a hard disk.

On a motherboard, RAM is present in PCB modules as shown in the figure below.

Types of RAM Modules:

Different types of RAM modules are shown above. You can differentiate these RAM modules by the CUTS on golden pins on the lower side of each module. Just notice that each type of RAM module has a cut or a notch on different positions along the length. RAM modules have been aligned vertically according to their date of origin and speed. SIMM modules were among the first types of memory to come and DDR4 RAM modules are the fastest and latest memory types. All the above types of RAM are Dynamic RAM.

RAM  is further classified into two types

1. DRAM: Dynamic RAM
2. SRAM: Static RAM

	DRAM	SRAM
Memory Cells Type	Capacitors	FET
Packing Density	High	Low
Speed	Low	High
Cost	Less	High
Function ( Used As )	Main Memory	Cache Memory

Working Diagram of Computer Memory

Cache Memory 

Cache memory is just like another memory that stores the data. Although all the programs, documents, or other media files you access in a computer run in RAM to make the processing faster, the processor, instead of searching for data in main memory(RAM), reads the data from cache(SRAM). The SRAM which consists of FETs has high speed compared to RAM which is built on capacitors.

Shadow RAM

The ROM  functions relatively slower than RAM. So it takes a longer time to access codes from ROM than from RAM. In order to speed up the ROM processing, the codes of ROM are copied into a region of RAM and are write-protected. This way the system now can access the ROM codes from RAM at a much higher speed. The region of RAM where the ROM codes are copied is called shadow RAM.

Other Types of Computer Memory

Virtual Memory

Virtual Memory is a memory management technique that extends the available memory beyond the physical RAM installed in the system. It utilizes disk storage (usually a portion of the hard drive or SSD) to temporarily store data and instructions that cannot fit entirely in RAM. When RAM becomes scarce, less frequently accessed data is swapped between RAM and disk storage dynamically. While virtual memory enables the execution of larger programs, excessive swapping can lead to performance degradation due to increased disk I/O operations.

Flash Memory

Flash memory represents a type of non-volatile memory that can be electrically erased and reprogrammed. It finds widespread use in portable storage devices such as USB flash drives, memory cards, and solid-state drives (SSDs). Flash memory offers fast read and write speeds, low power consumption, and shock resistance, making it an ideal choice for mobile devices and high-performance computing environments.

FAQs on Computer Memory

1. How do I determine the amount of memory I need for my computer?

The amount of memory you need depends on the tasks you plan to perform on your computer. For basic web browsing and office applications, 8GB to 16GB of RAM is usually sufficient. For more demanding tasks such as gaming or video editing, you may want 16GB or more.

2. How can I upgrade my computer’s memory?

To upgrade your computer’s memory, you typically need to identify the type and speed of the existing memory modules in your system and purchase compatible replacements with higher capacity or faster speed. Installation usually involves opening the computer case, locating the memory slots on the motherboard, and inserting the new memory modules. However, it’s recommended to consult your computer’s manual or seek assistance if you’re unsure about the process.

Final Words on Computer Memory

From the volatile speed of RAM to the persistent resilience of SSDs, understanding the intricacies of these memory types is paramount for optimizing system performance and catering to a broad spectrum of computing needs. As technology evolves, the boundaries of memory continue to expand, paving the way for innovations that drive the future of computing forward. By harnessing the power of diverse memory technologies, we unlock new possibilities for efficiency, reliability, and scalability in the ever-evolving digital age.