Seagate ST500LM021 Thin Hard Disk Drive 500GB SATA 6Gb/s 2.5-inch 7mm 7200RPM 3MTH WTY

Seagate Momentus ST500LM021 500GB 2.5-inch 6Gbps 7200RPM Thin SATA Hard Disk Drive

The Serial ATA interface provides several advantages over the traditional (parallel) ATA interface. The primary advantages include:

• Easy installation and configuration with true plug-and-play connectivity. It is not necessary to set any jumpers or other configuration options.
• Thinner and more flexible cabling for improved enclosure airflow and ease of installation.
• Scalability to higher performance levels.

In addition, Serial ATA makes the transition from parallel ATA easy by providing legacy software support. Serial ATA was designed to allow you to install a Serial ATA host adapter and Serial ATA disk drive in your current system and expect all of your existing applications to work as normal.

The Serial ATA interface connects each disk drive in a point-to-point configuration with the Serial ATA host adapter. There is no master/slave relationship with Serial ATA devices like there is with parallel ATA. If two drives are attached on one Serial ATA host adapter, the host operating system views the two devices as if they were both “masters” on two separate ports. This essentially means both drives behave as if they are Device 0 (master) devices.

The Serial ATA host adapter and drive share the function of emulating parallel ATA device behavior to provide backward compatibility with existing host systems and software. The Command and Control Block registers, PIO and DMA data transfers, resets, and interrupts are all emulated.

The Serial ATA host adapter contains a set of registers that shadow the contents of the traditional device registers, referred to as the Shadow Register Block. All Serial ATA devices behave like Device 0 devices. For additional information about how Serial ATA emulates parallel ATA, refer to the Serial ATA International Organization: Serial ATA (Revision 3.2).