Measures reported by UspCachePRateTest

The write pending rate indicates the ratio of write-pending data to cache memory capacity. The Performance Monitor panel displays the average and the maximum write pending rate for the specified period of time. When you display monitoring results in a short range, the panel also displays the average and the maximum usage statistics about the cache memory for the specified period of time. In addition, the panel can display a graph that indicates how well the write pending rate or the usage statistics of the cache memory changes within that period.

This test is used to identify the I/O activity of the CachePendingRate.