The H745P MX is a RAID controller for the PowerEdge MX740c and MX840c compute sleds. It is used as an interface in a multipath topology with the MX5016s storage sled for the MX7000 modular system.
The H745P MX is connected to the SAS IOM, which in turn connects to one of the SAS expanders in the storage sled. The expander in the storage sled is then connected to all the physical drives in the storage sled, providing one path between the H745P MX and a physical drive in the storage sled. With connections to both SAS IOMs, the H745P MX has two paths to each drive in a storage sled allowing for a multi-path configuration. If either a SAS IOM or a SAS expander in the storage sled is removed, then a path to the physical drive is removed from the SAS topology.