A.x445 supports PCI-X adapters
B.x445 can scale up to 16 processors
C.x445 supports redundant power supplies
D.x445 can expand I/O by adding the RXE-100
E.x445 comes standard with systems management software

A.DS4500 offers better connectivity to the IBM iSeries Servers.
B.DS4500 ships with remote volume mirroring （RVM） and Flashcopy services.
C.DS4500 offers virtual arrays and fibre tape backup options that make it a less expensive solution.
D.DS4500 offers storage manager software standard while EVA requires purchasing of the management software.
E.DS4500 offers a flexible solution customizable by the customer while EVA ships standard with a minimum of six disk enclosures.