Windows Server 2008 - Choosing a processor configuration

Windows Server 2008 comes in two processor configurations: 32-bit (also known as x86) and 64-bit (also known as x64). If you have a 64-bit processor installed in your system (and you probably do), it’s tempting to choose the 64-bit processor immediately to gain the perceived benefits that 64-bits can provide. However, the question of whether to use the x86 or x64 version isn’t always an easy one to answer because there are hidden pitfalls to consider.

Microsoft has also made it difficult to determine the benefits of 64-bit processing, which tends to make your decision considerably harder. The benefits of 64-bit processing always help the operating system, but you may not even notice these benefits in some cases because they’re slight when compared to the applications you run. To obtain the benefits of 64-bit processing, you must have 64-bit applications, so using a 64-bit operating system may not yield many benefits.

To make things more interesting, the 64-bit version of Windows requires signed drivers. This requirement can actually cause three problems. First, many vendors don’t have 64-bit versions of their drivers, so you don’t have a driver to install. In the past, resource administrators used third-party equivalents to overcome this deficiency, but these third-party products may not run in Windows Server 2008. Second, the vendors who provide 64-bit drivers may not have signed them. Because the 64-bit version of Windows Server 2008 doesn’t allow you to use unsigned drivers and there isn’t a way to get around this requirement, unsigned drivers are akin to having no drivers at all. Third, when a vendor does offer a signed 64-bit driver, you may find that the performance of that driver is lacking and that it doesn’t work as well as the 32-bit equivalent because it has received less testing. Providing a signature for a driver tells you only who produced the driver — it doesn’t signify that the driver has great performance and runs error-free.

Before you decide to use the 32-bit version of Windows Server 2008, you need to know that Microsoft has embarked on a campaign to move certain of its applications to the 64-bit environment. For example, when you read the requirements for Exchange Server 2007 carefully (see http://www.microsoft.com/technet/prodtechnol/exchange/2007/evaluate/sysreqs.mspx for details), you notice that you must run this product on a 64-bit version of Windows. Yes, the tools run on a 32-bit system, but the product itself doesn’t. As part of your evaluation, you must consider the current and future support plans of the application vendors you rely on for server applications.

The important issue to consider about virtual servers is that they don’t use resources as efficiently as physical servers. The underlying operating system uses resources, as does the virtual server software and each of the operating systems is used as a virtual server. A virtual server setup provides flexibility. It can also improve security by reducing the attack surface of your system and can make your setup more reliable. However, the cost in resources of using a virtual server setup is considerable.

You may encounter a situation where you don’t have a good processor decision to make. Every potential solution is equally bad. Although this book doesn’t discuss the process, you may find that you have to run multiple copies of Windows Server 2008 to meet all your needs. Some organizations meet this need by purchasing multiple physical servers and installing Windows Server 2008 on each one. However, one of the reasons that Microsoft has provided Server Core is its ability to run multiple copies of Windows Server 2008 on one physical server by using a virtual server setup. In fact, Microsoft plans to release specialized virtual server software for Server Core sometime after it releases the actual product. (The current rumor says that the virtualization software will appear about 180 days after the Windows Server 2008 release.) You can read more about using virtual servers to solve potential processor problems at http://blogs.dirteam.com/blogs/sanderberkouwer/archive/2007/07/09/virtual-server-core.aspx. It’s also important to read the administrator’s guide at http://www.microsoft.com/technet/prodtechnol/virtualserver/2005/proddocs/default.mspx.

Source of Information : For Dummies Windows Server 2008 For Dummies