The DAC960SX provides all the RAID disk array controller functions to build a fault tolerant storage system with fully transparent controller failover. Coupled with other fault tolerant system components, such as redundant fans and power supplies, the SX provides disk array features and performance for demanding server - I/O intensive applications. The SX is easily integrated into an existing 5¼" drive bay using the SXI enclosure, or becomes part of a custom enclosure with enhanced features, such as hot-swap, when used in accordance with the DAC960SX OEM Manual. SCSI bus support includes FAST and Ultra for both 8 and 16 bit devices.

A large cache memory reduces read latency using Mylex advanced read ahead algorithms. Write data is stored in mirrored buffers, one on each controller, to protect data in the event of a controller failure. The battery protected write buffer survives power interruptions of up to 72 hours (depending on cache memory size).Operating in duplex mode, two SX controllers are active and provide RAID storage connectivity with up to twice the performance of a single controller. Should one controller fail, the surviving controller transparently takes over I/O processing for the failed controller. The SX can also be used in simplex mode for entry-level arrays, and can later be seamlessly upgraded to duplex. And, with configuration information stored on the disk drives, a replacement controller comes on-line automatically.

• Dual Controller Capability - Two controllers can be used in partnership to provide a very high level of fault tolerance. If one controller fails, the other automatically invokes a "failover" and the host system continues to operate normally.
• Transparent Failover - In the event of "failover", the surviving controller "impersonates" the failed controller by responding to both SCSI IDs. Tasks sent to the failed controller’s ID are intercepted and executed by the surviving controller, so no special software or drivers are required.
• Active/Active Configuration - Dual controllers, when operating normally, provide twice the performance of a single controller. Competitive products using Active/Passive technology provide failure protection, but no performance benefits.
• High Performance - Supports sustained throughput up to 30 MB/sec with a single host channel. Dual controller configurations support up to 55 MB/sec.
• Protected Cache - Built-in battery backup unit protects the write cache from power interruptions for up to 72 hours. In Dual Controller configurations, the write cache is mirrored between controllers to ensure that data will be written to disk even if one of the controllers fails.
• Dual Host - Allows independent access from multiple systems, and protects against cable or host bus adapter failures (requires daughterboard). The Dual Host and Dual Controller features can be combined for extreme fault-tolerance with up to four host channels.
• Clustering Support - Reserve/Release support and the ability to assign LUNs to specific host channels ensure data integrity in multiple host configurations. Compatible with Unix and Windows NT Clustering (Wolfpack).