Difference between 32-bit and 64-bit processors

Published on September 22, 2015

Usually, when we hear about 32-bit and 64-bit processing, we immediately assume the latter is the newer and faster one. And truth be told, it is indeed newer and faster, but there will be always that slight difference. And simply knowing those differences could help you with future tech purchases and troubleshooting.


32-bit Processors

In computer architecture, a 32-bit was designed to provide faster computing processes. This is due to the fact that a 32-bit register can store 4 GiB of different values. The 4 GiB limit comes from its unit size which is bit (Binary), and then it has its 32nd exponential value. The equation would now be 232, resulting in your 4 Gib. This 4 GiB will now be known as your “Addressable Space”.  Since the earlier years of home computing were still behind compared with today’s technology, the 32-bit was indeed faster than its predecessors such as 8-bit and 16-bit.

Note: 1 GiB = 1,073,741,814 bytes = 1.074 GB

So what is a 32-bit processor? Well it is simply a processor that was designed using a 32-bit format. Using that format, it will have its limitations like having just 4 GiB of “Addressable Space”, meaning that it can only store 4 GiB of data. That data will now be the basis of how fast your computer can process programs and applications. So with your 32-bit processor, even though your available physical memory on your computer is up to 8 GB, only half of it can be fully utilized due to its 4 GiB of addressable Space.

32-bit Processors vs 64-bit Processors
Pentium M – an example of a 32-bit processor

64-bit Processors

By having a 64-bit format, it would then have an addressable space equal to 264, which is over 18 quintillion or 1.8 x 1019 of different values. But since current technology doesn’t seem to need a large virtual address space of 264 byes, and using such wide virtual addresses would be much more complex and have no real benefit, processors utilize 48-bits of virtual address instead. While it may seem like a big deficit on a 64-bit’s addressable space, a 48-bit will still have up to 256 Terabytes which is still a lot of space for your computer to work on.

IBM 64-bit processors were already out in 1961, but were only released for home computing in the early 2000’s. And ever since that time, 64-bit applications and programs started to emerge. This is simply because 64-bit can run faster and smoother than its predecessor.

Comparison Chart

32-bit Processors64-bit Processors
Addressable Space of 4 GiB (Can use up to 4 GB of RAM)Addressable Space of 16 Exbibyte (Can use up to 192 GB of RAM or higher)
64-bit applications/programs won’t workMost 32-bit applications/programs will work
Not recommended for multi-tasking and stress-testingIdeal for multi-tasking and stress-testing
Requires 32-bit operating systemBoth 32 and 64-bit operating system will work

32-bit Processors vs 64-bit Processors

So what’s the difference between a 32-bit processor and 64-bit processor? The big difference would be their addressable space. While a 32-bit can only work on a 4 GiB virtual address, 64-bit can work on 4 billion times more than that. This would now mean that computations and calculations on a 64-bit would be much faster. However, it would depend on how much RAM you have on your computer.

Let us say you have 4 GB of RAM to work with between the two processors; since the 32-bit can fully utilize the 4 GB of RAM as much as the 64-bit, there will likely be no significant differences. But when you increase the 4 GB of RAM to an 8 GB, you’ll notice significant differences since a 32-bit could only use so much addressable space and a 64 bit could fully utilize the full 8 GB of RAM. Take note though, depending on what programs and applications you’ll be running, you may not see any difference at all, since most of it does not require the whole RAM to run efficiently. Take Minesweeper (Windows game) and Photoshop (Graphics software) as an example; the former would not require that much RAM and would run on both processors efficiently, while the latter would perform much better on a 64-bit processor.

For their compatibility differences, it mainly affects your operating systems and software, since they both can be developed and programmed into a 32-bit or 64-bit format. For your OS compatibilities, a 32-bit processor can run only at 32-bit operating system, while a 64-bit processor can effectively use both 32-bit and 64-bit operating systems with no trouble. For your software compatibilities, we could say that both processors can run both applications, but the issue now would be your operating system. Since a 32-bit process can only work with a 32-bit operating system, only 32-bit applications will be compatible. With a 64-bit, it can use either a 32 or 64-bit operating system. With this logic, a 64-bit can run both 32-bit and 64-bit applications, as long as these applications are running with its compatible operating system.

So to summarize, since 64-bit processors have a huge advantage on addressable space, they prove to be much faster and more efficient. Although you should also consider other hardware or software used with your processors because these can cause a “bottleneck” (limited efficiency because of other factors’ capabilities).