What is the difference between a 32-bit and 64-bit CPU?

Computer CPUThe two main categories of processors are 32-bit and 64-bit. The type of processor a computer has not only affects it's overall performance, but it can also dictate what type of software it uses.

32-bit processor

The 32-bit processor was the primary processor used in all computers until the early 1990s. Intel Pentium processors and early AMD processors were 32-bit processors. The Operating System and software on a computer with a 32-bit processor is also 32-bit based, in that they work with data units that are 32 bits wide. Windows 95, 98, and XP are all 32-bit operating systems that were common on computers with 32-bit processors.

64-bit processor

The 64-bit computer has been around 1961 when IBM created the IBM 7030 Stretch supercomputer. However, it was not put into use in home computers until the early 2000s. Microsoft released a 64-bit version of Windows XP to be used on computers with a 64-bit processor. Windows Vista, Windows 7, and Windows 8 also come in 64-bit versions. Other software has been developed that is designed to run on a 64-bit computer, which are 64-bit based as well, in that they work with data units that are 64 bits wide.

Differences between a 32-bit and 64-bit CPU

The main difference between 32-bit processors and 64-bit processors is the speed they operate. 64-bit processors can come in dual core, quad core, and six core versions for home computing (with eight core versions coming soon). Multiple cores allow for increase processing power and faster computer operation. Software programs that require many calculations to function operate faster on the multi-core 64-bit processors, for the most part. It is important to note that 64-bit computers can still use 32-bit based software programs, even when the Windows operating system is a 64-bit version.

Another big difference between 32-bit processors and 64-bit processors is the maximum amount of memory (RAM) that is supported. 32-bit computers support a maximum of 3-4GB of memory, whereas a 64-bit computer can support memory amounts over 4 GB. This is important for software programs that are used for graphical design, engineering design or video editing, where many calculations are performed to render images, drawings, and video footage.

One thing to note is that 3D graphic programs and games do not benefit much, if at all, from switching to a 64-bit computer, unless the program is a 64-bit program. A 32-bit processor is adequate for any program written for a 32-bit processor. In the case of computer games, you'll get a lot more performance by upgrading the video card instead of getting a 64-bit processor.

In the end, 64-bit processors are becoming more and more commonplace in home computers. Most manufacturers build computers with 64-bit processors due to cheaper prices and because more users are now using 64-bit operating systems and programs. Computer parts retailers are offering fewer and fewer 32-bit processors and soon may not offer any at all.

Additional information

  • See our 32-bit and 64-bit definitions for further information and related links.