HP, IBM, and VCE were compared on their pre-configured cloud solutions. HP CloudSystem offers the most flexibility by supporting the integration of existing HP and third-party servers, storage, and networking components. It also supports multiple hypervisors and provides comprehensive support across all layers. IBM PureSystem is more limited as it does not support existing BladeCenter chassis or servers from other vendors. VCE Vblock offers the least flexibility as all server, storage, and networking resources must be purchased from VCE partners as part of the solution.