The "usage" tab provides access to extensive resource-wide metrics that are obtainable through the tree structure on the left hand side of the portal window and the charts and data on the right hand side.
To access any chart or data just click on any metric on the left hand side and you will be shown a graphical representation of that data.
For example, we chose "Avg CPU %: Idle: weighted by core hour: by CPU User CV" which provides us a data on average CPU idle weighted by core hours.
If you want to further analyze the data in the chart with different parameter, just click on any data element in the graph and pick a distribution you want to see:
Here, we went with CPI value.
You can do a lot more with these charts, for example, you can compare and organize them in Metric Explorer tab which provides the same extensive resource-wide metrics as in "Usage" tab. In order to do that, just click on the "Settings" icon corresponding to the name of the distribution and you would be taken to the "Metric Explorer" tab.
To further learn how to use the tools in "Metric Explorer" tab to play with your charts and data, please view this document.
To learn how to view job efficiency for your jobs, please view this document.
To learn how to export and download charts fro XDMoD, please view this document.