You may or may not be aware that the computer on your desktop is a 64bit computer!  For those who are aware, you may say 64bit is a non-event or 'wow the computer flies".  For those who are not aware, we would like to explain what 64bit is all about. 

In the current context, we define 64bit computer as a computer with a 64bit CPU which is the essential ingredient but not all ingredients for 64bit to function.  The technology is not new as it has been deployed in mainframe and high-end computers for decades.  At the mass market level, Intel and AMD started producing 64bit CPU as recent as 2005 for the price of and replacing the previous version of 32bit CPU.  We may see the change as a natural evolution process as CPU started from 4bit and evolved through 8bit, 16bit, and 32bit over time.  What does the bit number tell us?  It allows us to address a larger range of memories and to operate with a bigger chunk of instructions and data at one time.  For example, Windows XP does not recognize main memory of the computer over 3GB but its 64bit version goes beyond this limit comfortably.  In fact, we do need 64bit operating system to use the 64bit capabilities of the CPU. 

What if the application software such as Office is 32bit only?  It will not use the 64bit capabilities of the CPU or the OS but will run as 32bit with penalties from the overheads of managing 32bit under a 64bit equipped environment. 

(updated October 2008) The key criterion is the type of application software we run.  If the software is written for 32bit operation, we should use a 32bit operating system.  Modern computer hardware handles both 32bit and 64bit well.  

Do we need a 64bit computer?  The hardware is already 64bit and so we do not need to choose the hardware for 32 or 64bit.  We must know about the application software and determine if we need 32 or 64bit operating system (Windows or Linux).

Feel free to raise any questions you may have to the editors.