Page Faults (MEMmemPageFaultsPerSec)

Displays the number of hard and soft page faults in the processor.

Page Faults are normal for processors and do not necessarily imply a performance bottleneck. There are two kinds of page faults:

• Soft page faults--Occur when the processor needs a memory page that is not in the current working set but still in the standby list in main memory.
• Hard page faults--Occur when the processor needs a memory page that is no longer in the standby list in memory and must read the page from disk.

A soft page fault can be resolved without accessing a disk drive. A hard page fault must be resolved by physically accessing a disk drive.

Recommendations

Add memory if:

• the ratio of hard page faults to total page faults (that is, MEMmemPagesInputPerSec), is greater than about 0.05 to 0.10. If the ratio goes higher than this value, the system is spending too much time on paging activity, and you should consider installing additional memory.
• MEMmemPagesPerSec is greater than 10 (10 is a reasonable number, but may vary with disk hardware) and MEMmemPageFaultsPerSec is greater than MEMmemCacheFaultsPerSec. The system is paging too much and you should install additional memory.

Alternatives to adding memory:

• Instead of installing more memory, you may want to schedule memory intensive applications to run during off-peak hours, if possible.
• If your system uses multiple hard disks, you may want to spread the paging file across these disks and remove the paging file on the disk where the Windows system is located.

You can use composite parameters to monitor the relationship between MEMmemPagesPerSec, MEMmemPageFaultsPerSec and MEMmemCacheFaultsPerSec.

Thresholds for alarms and warnings

You should set appropriate Alarm and Warning values for your system based on the Baselining Overview topic.

Default properties