What’s the difference between RAM and ROM?
If you’re in the world of computing, then you undoubtedly hear the terms ‘RAM’ and ‘ROM’ thrown about. They are both abbreviations for types of computer memory, but they are very different in terms of what they do and how they operate. However, many people may not know what the differences between RAM and ROM. You can think of them like twins, similar in many ways, but with distinct personalities and functions.
What is RAM?
RAM stands for ‘Random Access Memory’ and it is the memory space where most of the actively-used data resides in your computer. This type of memory is often referred to as ‘volatile memory’ because its contents are erased when the computer is turned off. The RAM works by temporarily holding all the information that the CPU (Central Processing Unit) requires to perform its tasks. This includes everything from running programs to editing your document or watching a movie on your computer.
RAM is fast, and unlike other types of storage like disks and USBs, RAM provides quick access to data by allowing the CPU to retrieve data without having to retrieve it from a slower source like a hard drive. RAM is also used to cache data that is frequently accessed. The more RAM you have on your system, the faster it will run and the more applications you can open at once.
What is ROM?
ROM stands for ‘Read-Only Memory’, and it is a type of non-volatile memory that is used in digital devices to store data permanently and cannot be over-written. Unlike RAM, ROM chips store information permanently. The data or instructions stored in ROM is non-volatile and it’s not lost when the computer is turned off.
ROM chips are typically used to store firmware, which is code that executes specific functions on a device, such as the BIOS or UEFI firmware on modern computers, or the firmware on a smartphone or tablet. Firmware is critical for the functioning of the device, and without it, the device won’t boot up.
Differences between RAM and ROM
Although RAM and ROM are both types of memory, there are several differences between them. Here are some points to help understand the differences:
1. Volatility: RAM is volatile memory, meaning its contents are erased when the computer is turned off, whereas ROM is non-volatile memory, and its contents stay permanently on the device’s chip.
2. Read and Write Functionality: Both RAM and ROM are read-only, but only RAM can be written to. When you make changes to a file, add new software, or modify settings on your computer, those changes are written to the RAM. ROM does not support writing; its contents are permanent.
3. Data Storage: RAM is used to store the data that the CPU processes when running a program, whereas ROM is used to store the firmware code that does the basic initialization of the system, which is critical for boot-up.
4. Access Speed: RAM is much faster than ROM when it comes to reading and writing data. RAM provides quick access to data by allowing the CPU to retrieve data without having to go to a slower source like a disk drive. ROM is limited in terms of speed since it’s a read-only memory and the data is stored permanently.
Types of RAM
RAM comes in different types, each with different qualities and benefits. Here are the main types of RAM:
1. SRAM (Static RAM): SRAM is faster and more expensive than DRAM. It’s also more power-hungry, so it’s not commonly used in mobile devices. SRAM is used in cache memory and high-speed registers for caching frequently-used data. SRAM is also used in specialized industrial or scientific applications due to its low power consumption and fast processing ability.
2. DRAM (Dynamic RAM): Dynamic RAM is the more common type of RAM used in modern computer devices. It’s slower than SRAM and requires more power to function, but it’s more cost-effective to produce. DRAM is used in the main system memory for most applications.
3. SDRAM (Synchronous Dynamic RAM): SDRAM is a type of DRAM where data is synchronized with an external clock for higher data transfer speeds. It is commonly used in video cards and requires less power to run.
4. DDR (Double Data Rate) RAM: DDR RAM operates twice as fast as SDRAM. DDR2 and DDR3 followed DDR technology and also became popular for their faster memory speed and decreased power consumption.
Types of ROM
Like RAM, there are several types of ROM, each with different uses. Here are the most common types:
1. Mask ROM: Also known as ‘ROM on the chip’, Mask ROM is programmed with permanent data by the manufacturer before being shipped out. This type of ROM is used mainly in devices or systems that don’t require frequent updates, such as calculators and gaming machines.
2. PROM (Programmable ROM): PROM chips are programmed once by the user with special hardware. Once the programming is done, the PROM functions much like a mask ROM but cannot be changed or reprogrammed.
3. EPROM (Erasable Programmable ROM): EPROM chips can be erased and reprogrammed by using ultraviolet light or a special electrical pulse. This type of ROM is often used in industrial controls and embedded systems.
4. EEPROM (Electrically Erasable Programmable ROM): EEPROMs can be repeatedly reprogrammed by using electrical pulses to erase and rewrite the data. EEPROM is often used to store user data or small amounts of code in embedded systems.
Conclusion
Understanding the difference between RAM and ROM is key to understanding how computing devices work. RAM and ROM are both essential types of memory used in digital devices, but they serve different purposes. RAM is volatile memory that stores data related to active processes that is frequently accessed. ROM, on the other hand, is a non-volatile memory used to store permanent data that rarely changes, such as firmware. Knowing how these two types of memory work is vital when it comes to selecting the right devices for the task at hand. By understanding the differences between RAM and ROM, you will be better equipped to make informed decisions about choosing computer devices and memory upgrades.
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