To determine the vSAN CPU usage prior to 7.0U2 Do the following:
1) Get a reference point from the CPU performance graph.
2) Get the logical CPU cores for the host (reported in host summary).
3) Divide this number by the number of logical processors to get the percent of the host CPU used by vSAN. For example, if vSAN CPU usage reports 1510, on a host with 96 logical processors, the host CPU usage by vSAN is 1510 / 96 = 15.7%.