SATA II

The 1 chip

SATA II is the chip giant Intel and Seagate Seagate hard disk Intel giants in the SATA on the basis of development, its main characteristic is the external transfer rate from SATA to 150MB / s further increased to 300MB / s, moreover also includes NCQ ( Native Command Queuing, native command queue ), port multiplexer ( Port, Multiplier ) staggered start ( Staggered Spin-up ) and a series of technical characteristics. Simple external transmission rate of 3Gbps is not a true SATA II.

2 key techniques

The key technology of II 3Gbps SATA is the external transmission rate and NCQ technology. NCQ technology can drive the execution sequence optimization, avoid like the traditional hard disk that machinery according to the received instruction sequence for moving the magnetic head hard disk read and write a different position, in contrast, it will be received command after its ranking, ranking after the head will be highly efficient sequential addressing, thereby avoiding the head the loss caused by repeatedly moving, extending the life of the hard disk. Also not all SATA hard disk can be used NCQ technology, in addition to the hard disk itself to support the NCQ, also called motherboard chipsets to support NCQ SATA controller. In addition, NCQ does not support the FAT file system, only supports NTFS file system.

Because the SATA equipment market to compare a disorder, many SATA equipment providers in the market promotion of abuse" SATA II" growing phenomenon, such as certain so-called "SATA II" hard but only supports the 3Gbps and NCQ support, and some having only 1.5Gbps hard but support for NCQ, so, by Seagate ( Seagate ) led by the SATA-IO ( Serial ATA International Organization, SATA international organization, the SATA Working Group ) also announced that the SATA 2.5 specification, included the original SATA II has the most functions -- from 3Gbps and NCQ to the staggered start ( Staggered Spin-up ), hot swap ( Hot Plug ), port multiplexer ( Port Multiplier ) and compare the new eSATA ( External SATA, external SATA interface ).

Advantage

1 integrated connection

First of all, SATA2 disk improved on generation performance technology and maintenance measures and the introduction of the backplane interconnection technologies, also joined the NCQ, out-of-order execution, data distribution and collection, this technology is to improve the performance of the whole security enhancement, the launch of the new model of the SATAII hard disk using the new technology. At the same time joined the name EnclosureManagement maintainability measures, for example on the fan control, temperature control, a new hard disk, bad hard disk indicating, hard disk status indication etc.. In addition, it introduced from SCSI hard disk, back cross (BackplaneInterconnect) scheme, realization of the disk is directly connected to a backplane bus, get rid of the respectively connected to your port on the impossible, which can save a plurality of connecting lines connecting, contribute to the interior of the enclosure heat radiation, even in RAID hard disk under adverse conditions can also be replaced at any time.

2 speed

SATA2 hard disk can completely satisfy the network storage and server storage on the faster transmission speed requirements, at the same time can engage in a lot of hard disk connection, and the ideal speed can reach 300MB / s, with the transmission speed so that the data exchange can be more quickly and safely. Native command queue ( Native Command Queuing ) is a SATA2 hard disk in a very important technology, command queue is a line of the arrival of the command, they are in accordance with the sequence analysis and to arrange in order to optimize the execution sequence. The command queue, can be hard to provide more efficient real-time analysis command.

3 port selector

( PS ) port selector also have the characteristics of SATA2, PS mechanism allows two different host port connected to a hard disk, is hard to design a path. ( Port Multiplier ) technology is a port multiplier, Port Multiplier mechanism can make an active host with multiple hard disk information.