Wait until the cache is populated with data from typical application read and write activity, or fully warmed, before you begin tracking performance statistics. The amount of time until full cache warming varies depending on the working set size of the application data and the I/O access rate.
Cache metrics measure disk caching performance: average read and write latency, hit rate, insertion rate, and so on.
Flash Accel rolls up caching performance statistics for disks into averages or totals for the virtual machine on which the disks are configured.