Windows: Checking Page Fault Rates

If the operating system is not occupied with other functions, all the pages in the physical memory that are not in the address area of an active work process are swapped out (lazy page out) of the operating system as a preventive measure. If space is then required, the pages already swapped out only have to be deleted.

In a performing system, transaction ST06 thereby displays a high Pages out value and a small Pages in value in relation. This indicates that many of the swapped out pages were not overwritten and could not be included again through a work process without a page file access. Therefore, only the Pages in value is very important when assessing system performance. For more information, see  Special Features under Windows.

The following values for Pages in should not be exceeded:

Value Limit: Pages in under Windows

Pages in

Value Limit:

Short-term maximum for Pages in/s (Transaction ST06)


Long-term maximum for Pages in/h (Transaction ST06)


A high Pages out value has no bearing on system utilization. Only the Pages in value is used as a measure of system utilization. If the value limits are exceeded, the memory capacity of the machine is too small.