As Niels mentioned, SVM performance widget is part of System Manager dashboard in 8.3.1 release. This dashboard was not available with System Manager 8.3 release.
The SVM performance widget on the dashboard enables you to select the SVM and protocol for which you want to view the key performance parameters at the SVM level. The performance metrics consists of IOPS and latency for CIFS, NFSv3, iSCSI, and FC protocols that are allowed on a particular SVM. The refresh interval for this panel is 15 seconds, and it takes at least 15 seconds to load the first data point.
Note: Use Remember SVM checkbox, if the SVM selected has to be remembered everytime you navigate to the dashboard.