What is 32-bit Operating System
Have you ever wondered when you heard someone saying 32-bit Operating System or 64-bit Operating System? If you are not sure what it means then continue reading. By the end of this article, it will be clear to you.
Let us first understand how data is stored in the Computer. We all know that computers can only understand 0’s and 1’s and so everything (numbers, text, audio, video, etc.) is stored in binary format in the Computer.
Now, let’s look at the maximum number we can represent in base-10 using 8, 16, 32, and 64 bits.
The terms 32-bit or 64-bits are generally used to represent processor architecture. A 32-bit processor includes a 32-bit register. This register stores memory addresses and the processor uses these memory addresses to access the data.
The data/variables are stored in Computers at some memory addresses. These memory addresses are also integers and they also need to have certain bits to store these addresses. As mentioned above, these addresses will be stored in the register.
From the above table, we can understand that a 32-bit Operating System can access ²³² memory addresses i.e. 4,294,967,296 memory addresses which can be translated to 4 GB as per the calculation below. The memory space (RAM) is limited by the number of addressable memory. So a 32-bit Operating System (in other words, 32-bit processor) can access a maximum of 4 GB RAM (actually, it will be less than 4 GB because part of the registry is used for other temporary values).
= (4,294,967,296 / 1024) kB = 4,194,304 kB
= (4,194,304 / 1024) MB = 4096 MB
= (4096 / 1024) GB
= 4 GB
So how much memory can 64-bit Operating System access? Theoretically, it can access ²⁶⁴ (18,446,744,073,709,551,616) memory addresses which comes down to 17,179,869,184 GB of RAM. Yes, you read it right!! It’s a whopping 17 billion GB. But in practice, our computers are too small to use all this RAM. As per my reading/understanding, 64-bit Operating System has a limit of 16 TB RAM access. Similarly, 8-bit and 16-bit Operating Systems can access only 0.25 kB and 64 KB RAM respectively.
Check this link for the details about the maximum addressable memory (RAM) different versions of Windows Operating System can access.
Some of 32-bit Operating Systems
- Microsoft Windows: Windows 95, 98, NT, 2000, XP, Vista, and Server
- Linux: Red Hat, Mandrake, and Ubuntu
- Mac OS: Classic (84–2001) and OS X etc.
Some of 64-bit Operating Systems
- Microsoft Windows: XP Professional, Vista, Windows 7, 8, 10
- Linux: Red Hat 7.1
- Mac OS: OS X
As you have guessed a 64-bit OS is preferred over 32-bit OS because 64-bit can access more memory and will have more computational power.
Generally, a 32-bit software program can run on 64-bit Operating System but a 64-bit software can not run on 32-bit Operating System because 64-bit software will have 64-bit instructions which won’t be recognized by 32-bit Operating System.
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