@Kim_Bottu … Virtually Gung Ho
If you have read the VSAN 6.0 Design and Sizing Guide, you might have noticed that the overhead (CPU and RAM) for ESXi and VSAN services is calculated at 10% of the total resources. This applies to VSAN services usage only. As a best practive, add another 20% for the ESXi services. This leaves about 60% resources to run workloads.