As more high-density servers come online, businesses are increasingly requiring advanced RAID functionality in a small form factor. This is exactly the need addressed by the Adaptec 2120S card. This controller provides a number of advanced features for entry-level and mid-range servers, such as optimum capacity use of mixed size drives. The Adaptec 2120S RAID controller features Ultra320 SCSI and data transfer rates up to 320 MByte/sec on each channel. This performance increase is especially significant in storage systems performing large data transfers or connecting many drives on a single channel. Adaptec developed a new technology called Seamless Streaming to optimize Ultra320 performance, maximizing bus utilization and minimizing command overhead as multiple commands are transferred in a single connection and at higher speeds. Adaptec's exclusive optimized disk utilization allows the full available capacity to be used of all drives attached to the controller, even if the drive sizes are different. The card also makes it possible to create multiple arrays from a single set of drives. Online Capacity Expansion and RAID Level Migration allow users to adjust ever-changing storage needs on the fly. This powerful combination of features maximizes system resources and reduces downtime.