The 64 Bit Processor

by Mich
January 6, 2004

Apple, AMD, and Intel have now released versions of 64 bit processors, the computer world is rejoicing! But what does this mean to you?

The bit rating of the processor determines the largest mathematical number it can process in a single clock cycle. The largest number that can be processed is 2 to the power of the bit rating. Therefore a 32 processor can handle 4,294,967,296 or 4.3 billion bits in one clock cycle. Any number higher would take more than 1 clock cycle to perform. A 64 bit processor can handle 18,446,744,073,709,551,616 or 18.4 quintillion bits in one clock cycle. The 64 bit processor would be more able to handle very complex mathematics.

The bit count of a processor also determines how much memory the system can support and access. A 32 bit processor can support up to 4 gigabytes of memory in a pc. Only 2 gigabytes can be allocated to any given application. A 64 bit processor can allocate up to 4gb of ram to an application. How much memory can a 64 bit processor handle? Here is where the processors vary. We will be addressing ram capabilities under the specific processors.

There will also be changes with the types of programs and operating systems that the processors will be able to run. The 64 bit processor uses different architecture than the 32 bit processor did, therefore new programs will have to be made that can run on a 64 bit processor. So far there is Linux, Windows Server 2003 64 bit, Sql Server, and Windows XP 64 bit. The Unreal Tournament creators are working on a 64 bit version of their game, and there is also speculation that Microsoft is going to be releasing a 64 bit version of Exchange Server as well. Many other software companies are also working on 64 bit versions of their software. The problem here though is they are waiting to see the demand for the 64 bit architecture. Software companies want to see how much demand and support there will be for the hardware, and hardware companies want to see the demand and support for software before really proceeding. Some of the processor manufacturers are getting around this limitation though.

Apple G5

Apple and IBM teamed up to created the 64bit G5 processor for Macintosh computers. The G5 can reach speeds of up to 2ghz. This processor can address up to 8gb of ram and 4 terrabytes of physical memory leaving plenty of space for growth in the future. Good news as well, with this processor there won’t be a need to purchase all new software because the G5 will run 32 and 64 bit programs!

AMD Opteron/Athlon 64

The AMD 64 bit processor architecture only has 40 bits of memory registers as opposed to 64 bits of memory registers and therefore can only support up to 136gb of ram. Although memory vendors haven’t caught up with being able to supply this amount of ram yet, they are expected to catch up soon. Most users won’t even be able to see what they are lacking in the memory supported department either. A home pc rarely uses more than 1gb of ram as is. A cad operator or a server would be able to tell the difference though because they are high end users that utilize a lot of memory.

So far the greatest part of the AMD’s 64 bit processor is the fact that it can run in compatibility mode for 32 bit programs without a performance decrease. AMD designed its processor first to run with 32 bit operating systems then added in the 64 bit registers. This means that you can still use the 64 bit processor with your current programs and operating system as well as utilizing the newer 64 bit programs at the faster 64 bit speeds.

Intel Itanium

Intel has manufactured this processor for enterprise/large business servers. This processor has run into problems when looking at it from a desktop point of view because the processor is not backwards compatible with 32 bit programs without a serious decrease in processor/computer performance. When it comes to enterprise users the chip’s performance speaks for itself. Currently the Itanium system uses 64gb of ram. It is capable of using more and will use more once the ram manufacturers catch up.