SAS 9.1.3 Language Reference: Concepts, Third Edition, Volumes 1 and 2

performance statistics

are measurements of the total input and output operations (I/O), memory, and CPU time used to process individual DATA or PROC steps. You can obtain these statistics by using SAS system options that can help you measure your job's initial performance and to determine how to improve performance.

system performance

is measured by the overall amount of I/O, memory, and CPU time that your system uses to process SAS programs. By using the techniques discussed in the following sections, you can reduce or reallocate your usage of these three critical resources to improve system performance. While you may not be able to take advantage of every technique for every situation, you can choose the ones that are best suited for a particular situation.