What is the difference between ROM & RAM?
What is the difference between ROM & RAM?
Memory plays a vital role in the digital world. Without memory, it would not be possible for computers to do operations by retrieving data. Based on how long data is stored, there are generally two types of memory: primary memory and secondary memory. Examples of primary memory are RAM and ROM, and secondary memory examples include hard drives, CD ROM, etc. In this blog we will first discuss the difference between ROM and RAM memory, and then we will talk about memory and storage.
What is ROM?
ROM stands for Read Only Memory. It is a type of non-volatile memory used in computers and other electronic devices. Data stored in ROM cannot be electronically altered once the memory device is manufactured. It is useful for storing software or programs that don’t change during the life of the system, which is sometimes called firmware. Software applications can be distributed as plug-in cartridges that have only read-only memory.
There are several types of ROM depending on their application because, in some cases, the data inside them needs to be changed. Types of ROM are:
- PROM – Programmable Read Only Memory
- EPROM – Erasable Programmable Read Only Memory
- EEPROM – Electrically Erasable Programmable Read Only Memory
What is RAM?
RAM stands for Random Access Memory. Random access memory is another type of primary storage that stores data and machine code currently being processed and used by the computer. A RAM device allows data to be read and written in almost the same amount of time regardless of the physical location of the data inside the memory.
On the other hand, in secondary storage such as hard disks, CD-RW, DVD-RW, and older magnetic tapes, the time required to read and write data changes significantly depending on the physical location of the data inside the memory device. It happens because of mechanical limitations such as media rotation speeds and arm movements.
RAM is available in different forms, namely:
- SRAM – Static RAM which include Cache L1, Cache L2, and Cache L3
- DRAM – Dynamic RAM
These days, DRAM is the most popular RAM, used in computers and other electronic devices in the market.
What are the main differences between RAM and ROM?
While RAM and ROM are both primary memories, they are entirely different from each other in many aspects. Some of the key differences are as follows:
- RAM is random storage where data is lost in case of power failure. However, ROM saves original data if there is power loss. In other words, RAM is volatile memory, and ROM is called non-volatile memory.
- ROM means the data can only be read and not written. However, in RAM, data can be read as well as rewritten randomly.
- In a computer, we all know there is memory and a hard disk. In fact, memory is a sort of RAM technology, and ROM acts similarly to a hard disk. While both are memory, the speed of RAM is much higher than the speed of ROM. While RAM has data that has to be currently processed by the CPU and needs to be stored temporarily, ROM stores instructions that are required during the bootstrap of the computer.
- CPU cannot access ROM’s data unless its data is shifted and stored in RAM.
- ROM works like external storage such as SD card where your data is stored for a longer time.
- A RAM chip can store data of only a few gigabytes; however, a ROM chip can store multiple megabytes of data. Hence, RAM comes in a larger size with higher capacity.
What is the difference between memory and storage?
It is common for people to get confused between memory and storage. Many people even think both are the same. In reality, memory and storage are quite different terms. While memory is what your computer uses to store data temporarily, storage is where you can store your files and data permanently.
When you save a file, the data is stored from the memory to the storage drive. That’s why your computer runs slow when your computer is low on memory. It has to pull data from the storage drive so that the computer can use it for processing.
This is also the reason when your computer runs slow, experts recommend freeing up some memory by deleting unused data and files that you don’t need any longer.
On the other hand, storage is permanent and holds all of your files, regardless of whether you are using them currently or not. When you save a file, it is actually stored on your computer storage. And you can choose between internal and external memory, which you cannot do with RAM. While internal storage is part of the computer’s or mobile phone’s hardware, external storage comes as a separate device that needs to be plugged into the computer or phone. We need both memory and storage to run programs and applications properly.
Most modern secondary external storage come in the SSD form. Solid-state drives are the most common storage today and they are smaller and faster than hard drives (HDDs). SSDs are also noiseless and allow PCs to be slimmer and more lightweight.
What do servers use for storage?
To store large amounts of data of an organization, storage servers are typically used. But what do servers use for storage? Servers also use hard disk drives for storage of files. They use a program called archive to compress files so that huge amount of data can be stored in less memory space.
Modern server storage example is Dell MD1400, which is a solution for affordable storage expansion for Dell. It offers the flexibility of a hard drive in a 2U, 12-drive enclosure. This storage model can expand to 8 enclosures and up to 96 hard drives behind the PowerEdge Server.