Types of Desktop Memory

Despite being surrounded by all forms of computers for more than a decade now, only a margin of the population precisely knows what PC memory is all about.

We all know that computer is made up of different entities, but the definition and types of memory is still vague to most of us. All the praise computers get for easing out our daily tasks accrue to nothing but the memory.

It is the core of any computer because if not installed, a computer won’t be able to perform even the simplest tasks.

The music we store, the browser and the operating system etc. all rely on some on the other form of memory. From a layman’s point of view, we have two types of memory, RAM and Storage.

These form the stem of further classification, but we will talk about the same towards the end.

Types of Memory

Memory is basically divided into two types, Primary and Secondary, which is basically RAM and ROM. These are explained as follows:

1. Primary Memory:

It consists of Random-Access Memory (RAM) and Read-Only Memory (ROM). The data on this is stored as a mix-bag, CPU requesting such when needed. Both of these are connected directly to the motherboard enabling lighting fast access to the data persisting on them.

Random-Access Memory is super quick in performing operations. It can be written from/to as long as power is being supplied to it. As soon as plug is pulled, any data which is stored on the RAM will be lost and cannot be recovered anyhow, or in other words, RAM is a volatile memory.

When compared to expensive memory, it is costlier due to the operations it performs.

The operating system can also create a buffer to keep things steady or clean up the existing data to make space for new one. RAM has been further classified based on the workload environment, as explained below.

DRAM: Dynamic System Random-Access Memory or DRAM is a consumer-oriented form of RAM. There are multiple versions of this, denoted by DDR followed by a number, higher number accounting to latest generation. Currently, DDR4 is the latest DRAM available.

Cross-version compatibility isn’t a thing with DRAM, i.e. if you plan to pair DDR2 RAM with DDR3 RAM, it is a bad idea. DRAMs are energy efficient and small in size, consisting of only a transistor and capacitor each. Depending on the motherboard, you can install as many DRAMs as one wish to.

SRAM: Static Random-Access Memory or SRAM is a server focused form of RAM. When compared to DRAM, SRAM is way faster but is more expensive. Moreover, the SRAM is shipped with multiple transistors and cells, which makes it bulkier and power hungry.

All of these add up to the reason why this isn’t used in the consumer space in the first place. Although, CPUs might use this as a buffer cache within the CPU. It is also used as a DRAM for servers. The performance gains over SRAM is very noticeable, around two to three times.

It needs to be refreshed continuously, unlike DRAM, to keep data intact despite it being a volatile memory.

2. Secondary Memory:

It consists of Read-Only Memory (ROM). As the name might suggest, the computer is capable of only reading data from this type of memory and cannot write to it. ROM is connected to a motherboard using connector cable of some sort, and is kept close to the same.

ROM is a non-volatile memory. If you have any data stored and the computer loses power somehow, be it a power cut or shutdown done by the user, it shall remain as it is.

Hence, it falls under the category of non-volatile memory. The primary purpose of installing a ROM on computer is long-term storage. Most of the operating systems these days rely on ROM to store important files which help the core functions so it is a must have.

If one is installing such an operating system which needs to keep its load parts on ROM, then he/she must keep the same ROM installed until a replacement or upgrade is needed. ROM is slower when compared to RAM, as is cheaper. Some of ROMs might also use RAMs to speed up read/write speeds.

ROMs are further classified as follows:

PROM: Programmable Read-Only Memory consists of data loaded onto it by the manufacturer during the manufacturing process. It is read-only, hence the end user will not be able to perform any write tasks onto it. It is commonly used by IT companies.

EPROM: Erasable Programmable Read-Only Memory consists of data, which can be deleted and reprogrammed at a later point of time. To delete data, the user must expose the EPROM to an ultraviolet light which shall erase the data, and hence, can be reprogrammed.

EEPROM: Electrically Erasable Programmable Read Only memory draws similarity to EPROM in terms of basic function but the data has to be wiped using an electrical beam.

Commonly seem forms of ROM media are:

  1. Hard Disk Drives: Cheap and inexpensive way of storing data. The data is mechanically written onto the disk attached.
  2. Solid State Drives: Very fast medium of storage, has read write speeds up to 100 times faster than a normal HDD, but costs more. SSDs don’t use mechanical parts so it more durable as compared to HDDs.
  3. CD/DVD Drives: Ultra-portable form of ROMs, data can be copied to these and loaded onto another system without compatibility issues.
  4. Storage Severs/Network Attached Storage: Dedicated machines comprising multiple HDDs/SSDs, total of which can be used as a singular capacity.

RAM and ROM differ basically in speed and the volatility departments. Both perform different functions, each being core to computer operations. While RAM processes data needed at the time by the applications, ROM supplies such data to RAM.

Both of them are interdependent and it is impossible to boot a computer without having both (exceptions being the OS’ which are small enough to buffer in RAM).

Paul has more than 10 years of experience within the digital realm. He loves to talk about his ‘HOT’ girlfriend and when it comes to geeky boring topics, and nerdy technical issues he’s a magic man. Paul also enjoys reading and solving complex puzzles. "Give to the world the best you have and the best will come back to you" -Edward W. Bok 1929