Updated March 6, 2023
Difference Between RAM and ROM
RAM, otherwise called Random Access Memory, maintains the data only when it is in use. It stores the information in temporary forms and requires the power to store data. The size is more, and also, it is costly when compared with ROM. We can use RAM for both read and write operations. ROM (Read Only Memory) stores the content even if the system is not in use to store the information permanently. It can be used only for read operations, and the cost is very less. The size is small, and its capacity is also less. RAM is used in CPU cache, whereas ROM is used in microcontrollers.
RAM
- Every computer has some form of storage, which stores data and machine code currently under execution. A RAM, i.e. random-access memory device, provides the same purpose, which allows the read and writes of data in the same amount of time. RAM devices have many data lines to address this storage requirement. Modern world RAM devices are known to have volatile types of memory; the information would be lost if power is removed, even though non-volatile RAM is also being developed. RAM is also available in the form of integrated circuits. There are other non-volatile memories in the market, which have certain restrictions like allowing random access for a read type operation but won’t allow write operations.
- There are two types of RAM that are widely available in the modern computer world, SRAM, i.e. static RAM and DRAM, i.e. dynamic RAM. SRAM is expensive to produce, which stores every bit of data using a transistor memory cell state. SRAM is faster and needs less power than DRAM, thus utilized by the modern computer chiefly as cache memory. On the other hand, DRAM store a bit of data using a pair having a transistor and capacitor. Since it is cheaper to produce as compared to SRAM, they are widely used in computers across the world. Both SRAM and DRAM are volatile in nature since they lost their state when power is switched off for the system. More specifically, they are responsible for providing the main memory in the computer system.
ROM
- ROM cannot be easily modified, so they are fit to store the data, which won’t require modification for a longer period of time. One can say that this type of memory is hard-wired, cannot be altered after its manufacture. A recent version of ROM has arrived, contain a memory that is read-only for normal operation, although it can be programmed. EPROM, i.e. Erasable programmable read-only memory and EEPROM, i.e. electrically erasable programmable read-only memory, can be removed and re-programmed. However, this process takes time, relatively slower in speed and can be achieved at certain attempts.
- When the computer is powered on, a certain amount of memory is required to run the initial program, which is stored with ROM. This process is also known as booting or bootstrapping. In the modern computer, booting for the main processor is stored in ROM; other devices like a graphics card, hard disk, CD-DVD drives also utilizes ROM in the system. Mask-programmed ROM is the classical example of ROM, which physically encodes the data required to be stored. They are integrated circuits, and impossible to change their content. Another category of ROM, however, can be modified, which includes PROM, EPROM, EEPROM. ROM, which is electrically modified, their reading speed is faster than the writing speed. After applying for write protection, some reprogrammable ROMs become read-only memory.
Head To Head Comparison Between RAM and ROM (Infographics)
Below is the top 6 difference between RAM vs ROM
Key Difference between RAM and ROM
Both are popular choices in the market; let us discuss some of the major difference:
- RAM is random access memory and cannot hold the data without the power, whereas ROM is a read-only memory and can hold the data even without the power.
- RAM is a volatile storage medium to store the information, whereas ROM is a non-volatile storage medium to store the data.
- With RAM, writing data is a much faster and lightening process, whereas ROM, writing data speed is much slower as compared to RAM.
- RAM comes in two flavours, i.e. static RAM and dynamic RAM, whereas ROM has three varieties: Mask ROM, PROM, EPROM, and EEPROM.
- Data on RAM is accessed, read and erased multiple times, whereas on ROM, writing data is a relatively very slow process.
- RAM has usage with primary memory DRAM and CPU cache memory SRAM, whereas ROM is being used in BIOS, microcontrollers, and other electronic devices.
- RAM is expensive and does not come cheap, whereas ROM is way cheaper as compared to RAM.
- RAM has a large size with even higher capacity, whereas ROM is smaller in size and even with lesser capacity.
- RAM is a high-speed memory with reading-write operations, which happen at a fast pace, whereas ROM is slower speed memory, which is less prone to modification and can be done via an external program.
- With RAM, data on it can be altered multiple times, which explain its expansiveness, whereas ROM has data, which is permanent, even though it can be altered but at a very slow speed and that too, for a limited number of times.
RAM vs ROM Comparison Table
Below is the topmost comparison between RAM vs ROM
| The Basis Of Comparison | RAM | ROM |
| Data | RAM cannot hold data without power | ROM can hold data without power |
| Storage | A temporary medium of storage | A permanent medium of storage |
| Power | RAM chip is volatile, loses information if power is gone | ROM is nonvolatile, does not require a constant source of power |
| Operation | RAM chip is used in the normal operation of a computer | ROM is primarily used in the startup process of a computer or bootstrapping |
| Speed | Writing data to RAM is faster | Writing to ROM is much slower as compared to RAM |
| Example | RAM chips can store information, run the program and quickly switch between the tasks | PROM chip used with BIOS store the program need to begin the initial computer startup process |
Conclusion
In this RAM vs ROM article, we have seen both RAM vs ROM have their own set of merits and demerits. But both types of memory devices are mandatory for the efficient functioning of a computer device. ROM is cheap and can hold data permanently, but has its own set of limitations, like hard to modify the data and that too for a fixed number of time. RAM is expensive, but at the same time, data can be altered on it multiple times.
However, with a modern electronic landscape, ROM is no less incompetent. Removable storage media like USB drives, Storage data cards etc., is a sophisticated implementation of EEPROM, a read-only memory. Thus, both RAM vs ROM are meeting the requirement of technologies and performance of applications, with a large volume of data processing.
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