Enterprise resource planning systems (ERP), like SAP systems, build the backbone of the business processes in today’s large enterprises. This is why a weak performance of a SAP system tremendously decreases the performance of the user and thus of the enterprise. Today many SAP hosting providers make use of virtualization techniques, but disregard the impact of such solutions. In this paper we focus on the impact of virtualization solutions on the performance of SAP systems and follow a quantitative approach to ascertain several benchmark results. We make four contributions: 1) On the basis of a quantitative investigation we give a recommendation how to configure a SAP system for heavy workload. The recommendation helps to avoid hardware resource shortage. 2) We show that the average performance of a SAP system increases up to +2% if a container-based virtualization solution is used. 3) We show that the performance of a SAP system is decreased up to -33% if a Xen-based virtualization solution is used. 4) On the basis of the quantitative results we give recommendations for a new sizing process in order to meet the requirements for virtualized SAP systems.