Terminator power, Circuits and data path widths

Barracuda 9 Installation Guide, Rev. B

Terminator power

You usually will not need to change this option and can normally leave the drive configured as it was shipped from the factory. For information about how to change the terminator power option on your drive, refer to the appropriate drive-specific section.

I/O circuits and data path widths

•WD and DC models use differential I/O circuits. You cannot mix these models with single-ended models (N, W, WC) on the same SCSI bus. The circuits are incompatible with each other.

•W, WD, and WC models have a “wide” (16-bit) SCSI data bus rather than the standard (non-wide) 8-bit SCSI data bus; how- ever, you can use these wide drives on a standard (non-wide) 8-bit data bus.

Providing adequate cooling

The enclosure design must ensure adequate cooling for the drive. The maximum ambient temperature is 50°C.

The drive’s product manual (83329030) describes how to evalu- ate the air-flow design. The evaluation consists of ensuring that the case temperature of certain critical components remains within acceptable limits during drive operation.

We recommend orienting the drive or directing the air flow in a way that creates the least amount of air-flow resistance while providing air flow above the circuit boards and around the head and disc assembly (HDA). Also, choose the shortest possible path between the air inlet and exit. This minimizes the distance traveled by air that is heated by the drive and by other nearby heat sources.