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2128537 2009 年 10 月 07 日 12:00 Reading (loading. ..) Comments (0) Category: Personal Diary
Intel Intel and Seagate SATA hard drive giant Seagate developed on the basis of, and its main feature is the external transfer rate from SATA 1.5Gbps (150MB/sec) and further increased to 3Gbps (300MB/sec), also includes NCQ ( Native Command Queuing, Native Command Queuing), port multiplexer (Port Multiplier), staggered spin-up (Staggered Spin-up) and a series of technical features. The external transfer rate of pure not really 3Gbps SATA II.
SATA II technology is the key to the external transfer rate of 3Gbps and NCQ technology. NCQ hard drive instruction technology can optimize the execution order, avoid the traditional mechanical hard drives as the order in accordance with instructions received mobile hard disk read-write head at different positions, on the contrary, it will be sorted after receiving the command, sort head after the order will be addressed efficiently, thus avoiding the loss of head caused by repeated movement to extend drive life. Not all SATA hard drives also can use NCQ technology, in addition to the hard disk itself must support NCQ, but also requires the SATA controller chipset supports NCQ. In addition, NCQ technology does not support the FAT file system supports only NTFS file system.
the SATA device market is chaotic, a lot of publicity SATA equipment providers in the market abuse \does not support NCQ, but some of the hard disk but only with support 1.5Gbps NCQ, therefore, by Seagate (Seagate) led by the SATA-IO (Serial ATA International Organization, SATA International, the original SATA Working Group) has announced a SATA 2.5 specification, which included the original SATA II with most of the functionality - from 3Gbps and NCQ to the staggered start (Staggered Spin-up), hot (Hot Plug), the port multiplexer (Port Multiplier) and the relatively new eSATA (External SATA, external SATA interface) and so on.
advantage
First, SATA2 hard to improve the performance of the previous generation of technology and maintainability initiatives and the introduction of a backplane interconnect and many other technologies, also joined the NCQ, out of order execution, decentralization and the collection of data, the promotion of this technology is improve the overall performance of security, now flaunt the new SATAII hard disks are using these new technologies. Also joined the initiative called EnclosureManagement maintainability, such as fan control, temperature control, indicating a new hard disk, bad hard drive instructions, hard disk status indicator and more. In addition, it introduced from the SCSI hard drive, back each other (Backplane
Interconnect) programs to achieve the multiple hard drives connected directly to a backplane bus, out of each port to connect to their potential, so that eliminates the need for multiple cable connections, will help the internal cooling chassis Even in the hard disk under the adverse conditions RAID can also be replaced at any time.
SATA2 hard disk can fully satisfy the network storage and server storage requirements for faster transmission speed, while a large number of hard drives can be connected, and the ideal speed of up to 300MB / s, with such a transmission speed of data exchange can be made more quickly and security. Native Command Queuing (Native Command Queuing) is a very important SATA2 hard disk technology, the command queue is the arrival of the command line, they are in accordance with the analysis and re-arranged in order to optimize the execution sequence. Through the command queue, for hard real-time analysis provides a more efficient order.
(PS) SATA2 port selector is one of the features available, PS mechanism allows two different host ports to connect to a hard disk on top, to design a path for the second hard disk. (Port Multiplier) technology is the port multiplier, Port Multiplier mechanism can make the host an active exchange of information with multiple hard drives.
SATA stands for Serial Advanced Technology Attachment (Serial Advanced Technology Attachment, a hardware-based industry standard serial driver interface), by Intel, IBM, Dell, APT, Maxtor and Seagate co-drive interface specification proposed by the IDF Fall 2001 conference, Seagate announced a Serial ATA 1.0 standard, officially declared the establishment of the SATA specification. The external SATA hard drive specification theoretical transfer rate increased to 150MB / s, higher than the PATA standard ATA/100 50% higher than the ATA/133 have about 13%, and with the development of the next version, SATA Interface The rate can also be extended to 2X and 4X (300MB / s and 600MB / s). Its development plan, the future of SATA will also enhance the clock frequency to improve the interface transfer rate, so the hard disk can also be overclocked.
SATA interface requires hardware chip support, such as Intel ICH5 (R), VIA VT8237, nVIDIA's MCP RAID and SiS964, if the motherboard Southbridge chip does not directly support it, you need to choose a third party chips, such as Silicon Image 3112A chip, etc., but this will also produce some differences in hardware performance, and the driver is also more complicated.
SATA advantage: Support hot swap, transmission speed, the implementation of efficient use of SATA (Serial ATA) hard drive also known as serial port hard disk, PC hard drive is the future trend. In 2001, Intel, APT, Dell, IBM, Seagate, Maxtor that several major manufacturers committee composed of the formal establishment of the Serial ATA Serial ATA 1.0 specification. In 2002, although the serial ATA related equipment not yet officially listed, but the first to Serial ATA Committee has established a Serial ATA 2.0 specification. Serial connections Serial ATA, Serial ATA bus with embedded clock signal, with a stronger error correction capability than in the past the biggest difference lies on the transmission instruction (not just data) to check if that will automatically correct errors, which greatly improved the reliability of data transmission. Serial interface also has a simple structure, the advantages of hot-swappable.
serial hard drive is a new completely different from the parallel ATA hard disk interface type, the use of serial transmission of data is known. Relative to the parallel ATA is to have many advantages. First of all, Serial ATA continuous serial transmission of data, one can only send a data. SATA interface, this can reduce the number of pins, so that fewer number of connecting cables, the efficiency will be higher. Indeed, Serial ATA will be able to complete only four pins all the work, were used to connect the cable, connecting ground, send data and receive data, such a structure can also reduce system power consumption and reduce system complexity. Second, Serial ATA starting point higher, a greater potential for development, Serial ATA 1.0 data transfer rate up to the definition of 150MB / s, than the fastest parallel ATA (or ATA/133) can achieve 133MB / s maximum data transfer rate is still high, and the Serial ATA 2.0 data transfer rate of 300MB / s, SATA will eventually achieve 600MB / s maximum data transfer rate.
SATA physical design can be based on Fibre Channel (Fibre Channel) as the blueprint, so the four-core cable; demand voltage is substantially reduced to 250mV (maximum 500mV), compared with the traditional parallel ATA interface on a small 5V 20 times! Therefore, manufacturers can add Serial ATA hard drive on the advanced features such as hot (Hot Swapping) and so on. More importantly, the connection form, in addition to the traditional point to point (Point-to-Point) in the form outside, SATA also supports the \In actual use, SATA host bus adapter (HBA, Host Bus Adapter) is like the switch on the network, as can be achieved in the form and a separate channel for each hard drive so, that each SATA hard drives have a transfer exclusive channel, so there is kind of like parallel ATA master / slave control.
Serial ATA specification is not only based on the future, but also to retain backward compatibility with a variety of ways, does not exist in the use of compatibility issues. In terms of hardware, Serial ATA standard allows the use of converters with parallel ATA device compatibility, the converter can signal from the motherboard into the parallel ATA Serial ATA hard drive to use the serial signal, there are already several of this Class adapter / adapter market, which in a way protecting our existing investments, reduce upgrade costs; in software, Serial ATA and Parallel ATA maintains software compatibility, which means that manufacturers can no do not have to be rewritten to use any Serial ATA drivers and operating system code.
In addition, Serial ATA cable than traditional parallel ATA (Paralle ATA) connection is much simpler and easy retraction of the air flow and cooling within the chassis has improved significantly. Moreover, SATA hard drive and is always trapped within the chassis of different parallel ATA, highly scalable, which can be external, external enclosure (JBOD) not only provides better cooling and plug function, but also to multiple connection to prevent single points of failure; the design of SATA and Fibre Channel is exactly the same, so the transmission speed can do to ensure that different channels, which on the server and network storage is important.
Serial ATA can be described as a lot of advantages compared to parallel ATA, parallel ATA will become a cheap alternative. And the transition from parallel ATA to Serial ATA is also a general trend, it should be only a matter of time. The firms also promote SATA interfaces, such as Intel's ICH6 Southbridge chip series series compared ICH5 Southbridge chip, which supports 2 SATA interfaces increased from 4, while the parallel ATA interface, was reduced from 2 to 1 a; nVidia's nForce4 series chipsets already support SATA II or Serial ATA 2.0, but Samsung has developed by Marvell 88i6525 SOC chip interface, a new generation of SATA II hard drive, and will launch in early 2005.
2007 was enacted SATA2 and SATA2.5 standards, speed of 300MB / s
Tips: based on my personal experience, that SATA drives shortcomings evident in most of the board is very sensitive to overclocking, basically an overclocking motherboard will not recognize SATA hard disk, so advise those overclockers, be sure to buy a SATA hard drive Make sure your motherboard supports locking PCI-E/SATA, otherwise it may be hard for a overclocking situation can not be identified.
SATA plug damage, and generally do not pay attention caused by the majority of human reason, of course, useful for materials or design reasons suck, but it is recommended that you see more carefully, especially pulling a buckle SATA line.
Small Computer System Interface
small computer system interface (English: Small Computer System Interface; short: SCSI), one for computers and intelligent devices (hard disk, floppy, CD drives, printers, scanners, etc.) system-level independent processor interface standard. SCSI is an intelligent universal interface standard. It is a variety of computer and standard interface between external devices. This interface has the following features:
● SCSI interface is a common interface,
pandora bracelets, the SCSI bus can be connected on the SCSI host adapter and eight peripheral controllers, peripheral devices can include disk, tape, CD-ROM, rewritable CD drives, printers, scanners instruments and communications equipment.
● SCSI is a multi-tasking interface with bus arbitration function. Hanging in a number of peripherals on the SCSI bus can work. Equal share SCSI devices on the bus.
● SCSI interface can be synchronous or asynchronous transmission of data, synchronous transfer rate up to 10MB / s, asynchronous transfer rate of up to 1.5MB / s.
● SCSI interface, receives an external device. It's connecting cable can be up to 6m.
The original SCSI standard
the maximum synchronous transfer rate of 5MB / s, then the SCSI II provides two kinds of speed choices. A data transmission to improve the frequency, that is, Fast SCSI, the frequency doubled, up to 10MB / s; the other option is to increase the speed of transmission frequency also doubles the data path width increases by 8 increased to 16, that is, Wide SCSI, the maximum synchronous transfer rate of 20MB / s.
This interface is an easy system integration, reduce costs and improve efficiency of interface standards, more and more devices will use the SCSI interface standard, therefore, with a SCSI interface, SCSI CD-ROM drive, hard drives and more and more .
Linear Mode
