This article was previously published under Q139609
When using Performance Monitor, you might encounter high Memory: Pages/seccounter values that are not related to either paging file activity or cacheactivity. These high values may instead be caused by the an applicationsequentially reading a memory mapped file.
The following information is from the Performance Monitor counterdefinition information for the Memory Pages/sec counter:
Pages/sec is the number of pages read from the disk or written to the disk to resolve memory references to pages that were not in memory at the time of the reference. This is the sum of Pages Input/sec and Pages Output/sec. This counter includes paging traffic on behalf of the system Cache to access file data for applications. This is the primary counter to observe if you are concerned about excessive memory pressure (that is, thrashing), and the excessive paging that may result. This counter, however, also accounts for such activity as the sequential reading of memory mapped files, whether cached or not. The typical indication of this is when you see high number of Memory: Pages/sec, a "normal" (average, relative to the system being monitored) or high number of Memory: Available Bytes, and a normal or small amount of Paging File: % Usage. In the case of a non-cached memory mapped file, you also see normal or low cache (cache fault) activity.
As seen from the above information, a high number of Memory: Pages/sec isnot necessarily indicative of memory pressure or a Performance Monitorreporting error. It is necessary to monitor other counters, such as thosementioned above, to get the complete picture of what is happening in yourparticular case.