Difference between 32 bit and 64 bit Windows?

Infopackets Reader Gord S. writes:

" Dear Dennis,

I have Windows 8.1 64 bit installed on my PC. When downloading programs I see there are options for 32 bit or 64 bit. My question is: should I download both 32 bit and 64 bit programs? [Also, what is the difference between 32 bit and 64 bit Windows?] Thank you for your comments. "

My response:

That's a great question; thanks for asking. If you are running 64 bit Windows, you should download and install 64 bit versions of programs -- but only if they are available. If there is no 64 bit version available, then running the 32 bit version will work fine. To fully understand this answer, read below for more detail.

First: what is the difference between 64 bit and 32 bit?

When trying to understand 32 bit and 64 bit (whether it's an operating system or a program), it is perhaps easiest to explain the difference in terms of an analogy. Let's say we have 100 miles of highway; one side of the highway has 32 lanes, and the other has 64 lanes. Both lanes of the highway have cars that travel at the exact same speed: 100 MPH (miles per hour). Obviously, the highway that has 64 lanes will carry twice as many cars because it is wider in length. Likewise, a 64 bit program (or operating system) can handle twice as many bits at once. However, due to the posted speed restrictions (100 MPH), both sides of the highway still operate at the same speed.

Is 64 bit twice as fast as 32 bit?

No. 64 bit means that the operating system and CPU operate using 64 bit instruction set, but that does not mean that the CPU will run twice as fast as a 32 bit counterpart. The biggest advantage of 64 bit is that the operating system can handle more memory. By default, 32 bit operating systems can handle up to 4 gigabytes of RAM, whereas 64 bit operating systems can handle up to 192 gigabytes. The more RAM a system has available, the faster it is, because more frequently used information can be cached. That alone is one of the biggest determining factors of how fast a computer is (that, and having a solid state hard drive in the same system).

Will a 64 bit program run faster than a 32 bit program?

It depends on the program and the scenario. For example: if a program being used requires more than 4 gigabytes of memory to operate, then a 64 bit operating system would give the program more resources to work with, including the ability to cache information. This idea can be illustrated using MySQL, which is a popular database program that runs on both 32 bit and 64 bit operating systems. Significantly large databases should use 64 bit to take advantage of extra memory and caching that would otherwise not be available on a 32 bit system. This makes database queries and data acquisition much quicker. Also, some 64 bit programs may be coded more efficiently to run on 64 bit (compared to a 32 bit counterpart).

Should I install a 64 bit operating system on my computer?

If your PC has 4 gigabytes of RAM or more, installing a 64 bit operating system makes sense. Please note, however, that a 64 bit operating system will take up slightly more memory to operate than its 32 bit counterpart (example: Windows 7 32 bit or Windows 7 64 bit). The difference in memory is due to a number of factors, including memory addresses (32 bit memory addresses take up 4 bytes, whereas 64 bit memory addresses take up 8 bytes). Also, a 64 bit system will support both 32 and 64 bit programs, so there are twice as many operating system libraries (.DLL files) to take into account, which also eat up more memory.

About the author: Dennis Faas is the owner and operator of Infopackets.com. With over 30 years of computing experience, Dennis' areas of expertise are a broad range and include PC hardware, Microsoft Windows, Linux, network administration, and virtualization. Dennis holds a Bachelors degree in Computer Science (1999) and has authored 6 books on the topics of MS Windows and PC Security. If you like the advice you received on this page, please up-vote / Like this page and share it with friends. For technical support inquiries, Dennis can be reached via Live chat online this site using the Zopim Chat service (currently located at the bottom left of the screen); optionally, you can contact Dennis through the website contact form.