The IBM System Storage EXP3512 and System Storage EXP3524 expansion units are designed to affordably meet the demanding data requirements of today and tomorrow by building on over 30 years of design expertise. IBM's legacy in enterprise storage systems, with next-generation 6 Gbps SAS drive technology, enables the System Storage EXP3500 expansion units to deliver best-of-breed technology, reliability and performance. With two models available, the EXP3500 expansion units are 2U cabinet-mountable 6 Gbps drive enclosures that are designed to support either a total of twelve 3.5-inch SAS drives (EXP3512) or twenty-four 2.5-inch SAS drives (EXP3524) for optimal flexibility and efficiency. The EXP3500 expansion units can be a key component of a high-performance storage solution. With each external SAS port on the environmental service module (ESM) supporting a 6 Gbps x4-wide connection, the EXP3500 can achieve excellent throughput to the host.