Best performance and reliability within enterprise hard drives
Dual-port with full duplex operations
Online firmware update through Dell's Update Package (DUP)
Available in PowerEdge servers and PowerVault enclosures
SAS hard drives are true dual-port full duplex capable devices. This means that both ports on a SAS drive can simultaneously send or receive data (host dependent). Available in 2.5” and 3.5” form factors, SAS hard drives rotating at 10,000 and 15,000 RPM (revolutions per minute) are known as Tier-1, Online and Mission Critical devices. SAS drives at 10K & 15K offer the highest reliability of the the Dell enterprise hard drive offerings at a 1.6 Million hours MTBF (Mean Time Between Failure) rating. Also described as Traditional Enterprise, 10K and 15K SAS drives deliver the highest performance plus the highest reliability available in a rotating media storage device from Dell.
These 10K and 15K SAS drives are developed for the exacting requirements of speed and reliability due in mission critical applications. In order to achieve this level of performance there are multiple features of these drives that provide an advantage over the Tier 2 class used in business critical applications. These frequently include:
Higher quality sealing to prevent contamination
More shrouding and air control devices to maintain air pressure quality
Smaller platters with higher spin rates reducing access times
Faster seeks due to larger magnets, better bearings, and stiffer actuators
Longer and more stringent factory test to ensure the best quality drives
Higher quality motor to maintain the tight tolerances required at these higher speeds
Better design margin to handle rotational vibration issues.
These are just some of the features allowing these drives to have a better reliability (1.6 million hours MTBF) and higher performance than their Tier 2 cousins.
Available in both PowerEdge servers and PowerVault enclosures, Dell’s Serial Attached SCSI (SAS) interface and SAS hard drives are the successors to the SCSI (Small Computer Systems Interface) and SCSI hard drives previously found in the enterprise. The key difference is that SAS is a point-to-point interface whereas SCSI was a Bus-based interface. Pont-to-point means each device has its own full-bandwidth connection based on each specific drive/controller match up in capabilities as opposed to a bus-based interface where the entire set of devices on a bus would have to negotiate down to the slowest device. Today's SAS drives transfer data at rates at 3gigabit per second moving to as high as 6 gigabit per second in December 2009.
Dell SAS drives also have controlled firmware that has been specifically developed and tested for compatibility with select Dell RAID controllers delivering high reliability along with the assurance of compatibility for your information. Combined with the Dell Update Package (DUP), hard drive firmware can be updated on most hard drives without taking down the storage subsystem. Less downtime means higher productivity.