Email Servers

There are many different email server packages available in today’s market. You might use the built-in workgroup post office included with Windows NT or Windows 95. Or, you might purchase a third-party email server, such as Microsoft Exchange. In either case, email servers use system resources. The workgroup post office, for example, is based on a shared directory. This type of email server only utilizes the server’s file services. The processing is actually performed on the client. This doesn’t mean that the server will not utilize any other system resources, however. Any access to a shared file requires that the server use CPU cycles, system RAM, and network bandwidth. But an email server that only utilizes a shared directory will consume fewer resources than an application server, such as Exchange Server.

Exchange Server, which is the email server I use and recommend, is a true client/server application. One feature that makes Exchange Server such an exceptional and robust email server is that it uses a transaction log (similar to a relational database) for all internal file management. Exchange Server also uses quite a bit of system RAM (a minimum of 16MB), disk storage (120MB for a full install), and processor cycles. But, this is part of the price you must pay for a robust and highly capable email server.

When choosing an email server you should be aware of its requirements before installing it on your network. The main reason I use Exchange Server is because it is very scalable. It can handle as few as 1 client or as many as 500 clients on a single server. You can support more than 100,000 clients using multiple servers. Exchange Server can also store up to 16GB of data (private and public combined) per server. That’s a lot of email clients and storage capacity.

The actual requirements for your email server(s) will vary depending on your needs. At a minimum, however, you should allocate each server with at least a Pentium 133 processor, 64MB of RAM, 2GB hard disk, and a Fast Ethernet net-work adapter. If at all possible, an email server should not perform any other tasks except email services.

Database Servers

Just how much system hardware you need to support your SQL Server installations depends on what you want to do with SQL Server. The more you expect to get out of SQL Server, the more hardware you will require. But there are limitations to how much hardware you can throw at your SQL Server installation to achieve any real-world performance increases. The basic requirements fall into two categories: processor requirements and storage requirements.

SQL Server Processor Requirements

Windows NT Server and SQL Server execute on the Intel, MIPS, PowerPC, and Alpha processors. I would like to suggest a platform based on the number of transactions supported on the particular platform, but I have found that this varies too much from system to system. There are so many dependencies that any numbers I suggest here might not be accurate when you compare them to your system. Based on some early test results and recommendations from colleagues, I can say that the Intel Pentium Pro and DEC Alpha are superb performers. The Intel and Digital processors are also the only processors with a Windows NT future because Microsoft has discontinued support for the MIPS and PowerPC processors. So, I suggest you only consider these for your SQL Server installation.

At a minimum, you should consider only Pentium-based systems when considering the Intel processor line. This is because SQL Server is both processor and I/O intensive—the faster the processor, the faster the SQL Server performs, and the more clients it can accommodate. When making your purchasing decision, you might want to consider purchasing a uniprocessor platform that is expandable to a multiprocessor platform. This gives you the capability to increase your SQL Server performance levels by adding additional processors, if necessary.