Hi agray, thanks for your inquiry.
To see how much free resources you have, you will want to pay particular attention to the "Memory" donut chart. This chart shows you a breakdown of memory usage on all the nodes in your cluster. If you hover over the dark gray section of the donut, you will see the amount of memory that is reserved for Xcalar but is available to use. Likewise, you can hover over the lighter gray section of the donut to view the amount of memory that is available in your server and is not being reserved for Xcalar.