What is a 64-bit CPU without a 64-bit OS?
So far we have been talking about the capabilities of the processors based on their architecture, but there is a key point to be made here. The full use of a processor is only as good as the software written for it. Running a 64-bit processor with a 32-bit operating system is going to end up wasting a large amount of the computing potential of processor. The 32-bit operating system is only going to use half the registers of the processor thus limiting its computing ability. It will still have all the same limitations on it that an existing 32-bit processor has with the same OS.
This is actually a fairly large problem. Most architecture changes such as 64-bit processors generally require a completely new set of programs be written for them. This is a large problem for both the hardware makers and the software makers. The software companies don't want to write the new software until the hardware is out there to support their software sales. Of course, the hardware people can't sell their product unless there is software to support it. This is one of the major reasons why enterprise CPUs such as the IA-64 Itanium from Intel had problems. There was little software written for the architecture and its 32-bit emulation to run the existing operating systems severely crippled the CPU.
So, how are AMD and Apple getting around this problem? Apple has started added 64-bit patches for its operating system. This adds some additional support, but it is still running on a 32-bit OS. AMD has taken a different route. It has designed its processor to handle the native x86 32-bit operating systems and then added additional 64-bit registers. This allows the processor to run 32-bit code as effectively as a 32-bit processor, but with the current 64-bit versions of Linux or the upcoming Windows XP 64 it will utilize the full processing potential of the CPU.
Is the Time Right for 64-bit Computing?
The answer to this question is both yes and no. The industry is reaching the limits of 32-bit computing for much of the higher end computer market such as enterprise and power users. If computers are to increase in speeds and processing power, it is necessary to make the jump to the next generation of processors. These are systems that generally require much more memory and large number calculations that will get the direct benefits of a 64-bit platform.
Consumers are a different matter. Much of the tasks that the average consumer does on the computer are more than adequately covered by the existing 32-bit architecture. Eventually, users will get to the point where the switch to 64-bit computing will make sense, but currently it does not. How many consumers out there will likely even have 4 gigabytes of memory in a computer system even in the next two years?
The real benefits of 64-bit computing will eventually trickle down to the consumers. Manufacturers and software developers like to limit the variety of products that they have to support to try and reduce costs. Because of this, they will eventually focus solely on the production of 64-bit hardware and software. Until that time, it is going to be a bumpy ride for those who choose to be early adopters.
