Home > Workload Solutions > SAP > Guides > SAP HANA TDI Guides > Dell Validated Design for SAP HANA Scale-Out TDI solutions on Dell PowerEdge Systems > Scale-up and scale-out deployments
Scale up means increasing the size of a physical machine by increasing the amount of RAM that is available for processing.
Scale out means combining multiple independent computers into one system. The main reason for distributing a system across multiple hosts is to overcome the hardware limitations of a single physical server. In an SAP HANA system where a load is distributed between multiple servers, each index server is usually assigned its own host to achieve maximum performance. For more information, see Scaling SAP HANA.