Why Is Performance Important?

If you have ever sat waiting for a computer to do something, (while pounding on your desk, cursing, and wondering, "What is taking so long?"), you know why it is important to have a fast and well-tuned computer system. Although not all performance problems can be easily solved, understanding why things are slow can mean the difference between fixing the problem in software, upgrading the slow hardware, or simply throwing the whole computer out the window. Fortunately, most operating systems, Linux in particular, provide the tools to figure out why the machine runs slowly. By using a few basic tools, you can determine where the system is slowing down and fix the parts that are running inefficiently.

Although a slow system is particularly annoying to end users, application developers have an even more important reason to performance tune their applications: An efficient application runs on more systems. If you write sluggish applications that need a zippy computer, you eliminate customers who have slower computers. After all, not everyone has the latest hardware. A well-tuned application is usable by more customers, resulting in a bigger potential user base. In addition, if potential customers must choose between two different applications with similar functionality, they often choose the one that runs faster or is more efficient. Finally, a long-lived application likely goes through several rounds of optimization to cope with different customer demands, so it is crucial to know how to track down performance problems.

If you are a system administrator, you have a responsibility to the users of the system to make sure that it runs at an adequate performance level. If the system runs slowly, users complain. If you can determine the problem and fix it quickly, they stop complaining. As a bonus, if you can solve their problem by tuning the application or operating system (and thus keep them from having to buy new hardware), you make company bean counters happy. Knowing how to effectively use performance tools can mean the difference between spending days or spending hours on a performance problem.