Migrating from Windows Server 2003: 64-bit vs. 32-bit

January 5, 2015

Windows Server 2003 End of Life

On July 14, 2015, Windows Server 2003 Microsoft support will end. Meaning, after that date, there will be no more security fixes, hot-fixes, patches, or any other type of development for Server 2003 from Microsoft. It also means that if you have an issue and call in for Microsoft support, they will no longer open a support case for you. To find out the information from the source and to get ideas on how to move forward, click here. Over the next few months, we will be presenting blogs with information on migrating from Windows Server 2003. In this blog I am going to discuss a topic that is a major factor in migration.

Moving from 32-bit to 64-bit

One of the key points involved in moving off the Windows 2003 platform is going from 32-bit computing to 64-bit. 32-bit and 64-bit computing refer to a change in the instruction set for processors (CPUs) and how processors handle memory. Bits (binary digit) refer to the smallest units of computer data (a value of 1 or 0). As the number of bits in a computational value increase, the amount of data the value can hold increases. A 64-bit value exponentially holds a greater amount of data than a 32-bit. This difference is exhibited the most in physical memory addressing. The key differences of 64-bit computing over 32-bit computing is more memory. Memory limits in 32-bit Windows Operating Systems (OS) depended on the version in use and the 32-bit address space. Windows Server 2003 Standard had a limit of 4GB of memory, while Datacenter and Enterprise had a 64GB limit. In a 64-bit world, the Windows OS version still controls memory limits, but the 64-bit address bar has been raised. Windows Server 2012 Standard and above have a memory limit of 4TB. In fact, hardware is actually the primary limiting factor over software.

There is a Windows Server 2003 64-bit edition, but the adoption rate of that version was extremely low. The vast majority of Windows 2003 Server implementations were 32-bit. This happened for a number of reasons. The 64-bit server product was bleeding edge when it was introduced. Until Windows Server 2008, development for 64-bit products was not mainstream. Few software vendors factored in 64-bit compatibility in their code until Windows Server 2008. On the consumer side, 32-bit was the comfortable norm and 64-bit was factored in only when there were obvious gains. Requirements and advantages in Exchange and SQL were some of the primary factors for using the 64-bit version of 2003 over the 32-bit version. The number of users you could connect to one server through terminal services was greatly increased, but then you had to make sure that you were using software that worked in 64-bit terminal services.

It’s all about compatibility

So, what does all this mean in relation to migrating off Windows Server 2003? Compatibility. Will the software we have running in Windows Server 2003 work in 64-bit 2008 or 2012 servers? Will we have software drivers available on 64-bit that are as comprehensive as the ones we used in 32-bit systems? 64-bit servers are backward compatible and will run 32-bit applications, but not all 32-bit applications are 64-bit compatible. Applications with high resource demands probably moved towards 64-bit computing a while ago to take advantage of the increase in memory and processing power. However, we still have the issue of legacy software. We may only have licenses for a certain version of an application. We may need to pay for licensing of a later version. Or the licensing was based on the server OS. For instance, our 2003 Terminal Server CALs will not work with 2008 or 2012. We will need new licenses for that. What if there is no upgrade for that legacy system that will only work on a 32-bit system? All software issues will need to be researched and a plan developed to move forward.

Look for upcoming blogs, where we will discuss the research and testing needed, peripheral drivers (printers, scanners, etc.), SQL and Exchange requirements, backup solutions and more. Stay tuned and as always, please feel free to post your questions or comments below. You can also email me directly.


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