The SAS / SATA technology offers a performance improvement over traditional SCSI connections.
Serial Attached SCSI (SAS) and Serial ATA (SATA) are point-to-point serial peripheral interfaces
in which controllers are linked directly to disk drives. This technology supports full-duplex signal
transmission up to 6Gb/s. SAS devices can communicate with both SAS and SATA devices. A key difference between SAS and SATA devices is, that SAS devices can have two data ports, of which each resides in a different SAS domain. This enables complete failover redundancy. If one path fails, there is still communication along a separate and independent path.

SAS9200-8e 6Gb/s 8ext PCIe FH/LP
The LSI SAS9200-8e, dual port, host bus adapter provides high performance connectivity for external JBOD and external RAID enclosures. The LSISAS9200-8e provides 8 lanes of 6Gb/s SAS connectivity to 8 lanes of PCI Express 2.0 5Gb/s performance to eliminate bottlenecks. Performance is based on the LSISAS2008 IO controller that highly integrates the latest enhancements in PCI Express and SAS technology. The HBA supports up to 512 SAS 2.0 compliant devices.

The LSI SAS9200-8e has two (x4) external mini-SAS connectors (SFF8088) enabling a low profile solution that can achieve over 320,000 IOPs. Automatic speed negotiation for SAS and SATA data transfer rates of 1.5, 3 and 6Gb/s per lane assures legacy compatibility while new systems can benefit from T-10 Protection Information Model for early detection of and recovery from data corruption, and Spread Spectrum Clocking (SS C) for minimal EMI.