When reading about PCs and servers, you'll often see the CPU described by the number of bits (e.g., 32-bit or 64-bit), here's a little info about what that means.

32-bit refers to the number of bits (the smallest unit of information on a machine) that can be processed or transmitted in parallel, or the number of bits used for single element in a data format. The term when used in conjunction with a microprocessor indicates the width of the registers; a special high-speed storage area within the CPU. A 32-bit microprocessor can process data and memory addresses that are represented by 32 bits.

64-bit therefore refers to a processor with registers that store 64-bit numbers. A generalization would be to suggest that 64-bit architecture would double the amount of data a CPU can process per clock cycle. Users would note a performance increase because a 64-bit CPU can handle more memory and larger files. One of the most attractive features of 64-bit processors is the amount of memory the system can support. 64-bit architecture will allow systems to address up to 1 terabyte (1000GB) of memory. In today's 32-bit desktop systems, you can have up to 4GB of RAM (provided your motherboard that can handle that much RAM) which is split between the applications and the operating system (OS).

The majority of desktop computers today don't even have 4GB of memory installed, and most small business and home desktop computer software do not require that much memory either. As more complex software and 3D games become available however, we could actually see this become a limitation, but for the average home user that is very far down the road indeed.

Unfortunately, most benefits of a 64-bit CPU will go unnoticed without the key components of a 64-bit operating system and 64-bit software and drivers which are able to take advantage of 64-bit processor features. Additionally for the average home computer user, 32-bits is more than adequate computing power.

When making the transition from 32-bit to 64-bit desktop PCs, users won't actually see Web browsers and word processing programs run faster. Benefits of 64-bit processors would be seen with more demanding applications such as video encoding, scientific research, searching massive databases; tasks where being able to load massive amounts of data into the system's memory is required.

While talk of 64-bit architecture may make one think this is a new technology, 64-bit computing has been used over the past ten years in supercomputing and database management systems. Many companies and organizations with the need to access huge amounts of data have already made the transition to using 64-bit servers, since a 64-bit server can support a greater number of larger files and could effectively load large enterprise databases to into memory allowing for faster searches and data retrieval. Additionally, using a 64-bit server means organizations can support more simultaneous users on each server potentially removing the need for extra hardware as one 64-bit server could replace the use of several 32-bit servers on a network.

It is in scientific and data management industries where the limitations of the 4GB memory of a 32-bit system have been reached and the need for 64-bit processing becomes apparent. Some of the major software developers in the database management systems business, such as Oracle and SQL Server, to name just two, offer 64-bit versions of their database management systems.

While 64-bit servers were once used only by those organizations with massive amounts of data and big budgets, we do see in the near future 64-bit enabled systems hitting the mainstream market. It is only a matter of time until 64-bit software and retail OS packages become available thereby making 64-bit computing an attractive solution for business and home computing needs.