Physical Memory vs Virtual Memory: What You Need to Know

In this article, we will provide the most fundamental information on the difference between virtual and physical memory. If that sounds interesting to you, let’s explore this topic together.

Understanding Physical Memory

When examining the history of physical memory development, it began with technologies such as Williams-Kilburn tubes, delay lines, and rotating magnetic drums. Till the 1950s, the most used approach was considered to be magnetic core memory, and it continued till the 1970s. After that, a new technology appeared, and it was semiconductor memory.

Such progress led to the creation of well-known RAM or also it can be called primary or physical memory. Random-access memory is usually located on the motherboard, and it is volatile and has some size limitations because of the RAM chip. For its proper functioning, it requires constant data flow, and power troubles can cause obvious issues with information erasing.

Access to the physical memory can be received linearly. Moreover, this memory contains instructions for program execution, and the CPU can access this type of memory directly.

Usually, all the programs are stored on the hard disk, and it takes much longer for the CPU to access this information on the hard disk. Whereas, when such programs are stored in the physical memory, the CPU can process such data way quicker.

What Is Virtual Memory

Virtual memory can be described as a strategy of memory management that may be considered as the most extensive memory that is available. We have already covered some aspects of the physical memory, and it is extremely limited according to its size, whereas virtual memory allows us to expand the needed resources greatly.

A virtual approach towards the memory gives a possibility to significantly extend the limitations of the physical memory. Among all the various methods of extending is to move unused RAM storage to the secondary storage.

So, let’s try to understand how this virtual memory actually functions. So, virtual memory can be represented in the form of pages, and they can be explained as specific atomic units that can store huge amounts of information.

For instance, you are a professional or amateur gamer who installs the game on the hard disk or any other secondary storage. Not all the game files are loaded into the RAM, but when you start playing RAM stores specific parts of the game.

The functioning of the virtual memory occurs with both software and hardware to map virtual to physical address. For the translation of these addresses, the MMU or memory management unit is used.

In the OS, users see logical addresses but not physical ones, and the system translates these addresses during the execution of certain tasks.  

Key Differences Between Physical and Virtual Memory

Now, when you have some general understanding regarding virtual and physical memory, let’s review their key differences.

Let’s start with the physical memory:

• It is actually random-access memory or RAM.
• It functions based on swapping.
• Directly access the CPU.
• It is limited based on the RAM size.
• In terms of speed, it is faster.

Virtual memory differences:

• This is actually a memory management technique.
• It functions on the basis of paging.
• It cannot directly access the CPU.
• The limitations are based on the disk size.
• This memory is slower when compared to the physical.

Summary and Final Thoughts

To conclude, physical memory is smaller when compared with the virtual one, but it is way faster, because it is always available and easily accessible. So, these are just two memory types that have various methods of functioning, size, speed, and limitations.