A virtualized storage system comprises at least one host, at least one virtual array, a backend array and a management server. The host requests storage operations to the virtual array, and the virtual array executes storage operations for the host. The backend array, coupled to the virtual array, comprises physical storage for the virtual array. The management server determines the efficiency for the virtual array. The management server determines an input throughput data rate between the host and the virtual array based on storage operations between host and virtual array. The management server also determines an output throughput data rate, from the virtual array to the backend array. The output throughput data rate is based on the storage operations that require access to the backend array. The management server determines the efficiency of the virtual array using the input throughput data rate and the output throughput data rate.