What happens when a 32-bit program runs on a 64-bit machine?
Interesting Facts!
You must have heard a lot about 32 bit and 64 bit systems and how they are different from each other. Just to let you know, there are two types of computer architecture.
One is 32 bit, and the other is 64 bit. The difference between these two architectures lies in the number of the memory address.
A 32-bit system has a 32-bit register and can store 2 32values while the 64-bit system has a 64-bit register and can, therefore, access 2 64values. So, the 64-bit system is much larger in terms of memory address than a 32-bit system. Also, a 64-bit system has more power and can process more data at once than a 32-bit system.
But, questions like ‘Can a 32-bit program runs on a 64-bit machine?’ and ‘What happens when a 32-bit program runs on a 64-bit machine?’ are quite common and spark interest. Sometimes, you may need to run a 32-bit program on a 64-bit machine, but will it work?
Today I’m going to answer this question of yours so that you can avoid confusion about what applications can work on a 64-bit machine. Let’s now take a look at what happens when you run a 32-bit program on a 64-bit machine.
Can you run a 32-bit program on a 64-bit machine?
To put it in simple words, if you run a 32-bit program on a 64-bit machine, it will work fine, and you won’t encounter any problems. Backward compatibility is an important part when it comes to computer technology.
Therefore, 64 bit systems can support and run 32-bit applications. So now, the older applications are useful, and they can run seamlessly.
What happens when you run a 32-bit program on a 64-bit machine?
When you install a 64-bit program on a 64-bit machine, it’s installed in the ‘Program Files’ directory of your computer. But, when you install a 32-bit program, you will notice that the application is stored in another folder, named ‘Program Files (x86)’.
The reason for these two separate folders is that the operating system wants to keep the 64 bit and 32-bit libraries different from each other.
If you have a 32-bit system, then there is only so much you can do. You will have to install a 32-bit operating system on it and can only run 32-bit programs. But, if you have a 64-bit system, you have two options. Either you can install a 64-bit operating system, or you can install a 32-bit operating system on it. Similarly, having a 64-bit operating system means that you can run both 32-bit and 64-bit applications on it.
Furthermore, if you run a 32-bit program on a 64-bit machine, it will run perfectly because the program will take the computer as if it was a 32-bit machine. This happens because the processor enters a special mode and hides all the 64-bit extensions and libraries.
If the 32-bit application accesses the registers, the instruction registers will only take up 32 bits. The remaining upper 32 bits of each 64-bit register will be zeroed.
However, the only issue will be that while running a 32-bit program on the 64-bit machine is that the processor will not run to its full capacity. Also, the 32-bit program will not be able to address the whole RAM, and some resources of the machine will go to waste.
Final words
When a 64-bit machine runs a 32-bit program, the whole process will go smoothly and flawlessly. The 32-bit program will see and treat the computer as a 32-bit machine. The program will use the registers and resources as needed and will run without any issues.
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Originally published at https://www.codixlab.com on February 29, 2020.
