System Storage DS4700 Express model 72 is part of the DS4000 series storage products that address the needs of midrange and departmental storage requirements. It is designed to deliver high performance with advanced function and high availability. This model employs sixth-generation architecture that delivers 4 Gbps FC connectivity directly to host servers, SAN fabric, and disk drive expansion enclosures.DS4700 Express models come in compact, 3U rack-mountable enclosures that contain dual intelligent, high-performance RAID controllers. They can accommodate up to 16 E-DDMs for up to 4.8 TB internal physical storage capacity. Model 72 comes with 4 GB cache (2 GB per controller). Model 72 employs eight 4 Gbps FC host ports and four 4 Gbps FC drive ports.