Compaq 3200 manual Wide-Ultra2 SCSI Technology, Wide-Ultra2 SCSI Benefits

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The array accelerator, with backup batteries, is located on a removable daughterboard (see Figure 1-1). For information on daughterboards, see the Smart Array 3200 Controller Installation Guide. Although controller failure is not anticipated, the Array accelerator can be detached from a Smart Array 3200 Controller and attached to a replacement Smart Array 3200 Controller. If the configuration information stored in the Array accelerator matches that stored on the drives, any valid posted-write data being held in the cache will be written automatically to the drives attached to the replacement array controller. Thus, data being held in the array accelerator memory can be recovered despite failure of the main Smart Array 3200 Controller board. Refer to Appendix F, “Replacing the Array Accelerator,” for specific information.

Wide-Ultra2 SCSI Technology

The Smart Array 3200 Controller uses Wide-Ultra2 SCSI technology for improved performance. Wide-Ultra2 SCSI uses Low-Voltage Differential (LVD) signaling to enables maximum burst rates on the Wide-Ultra2 SCSI bus of 80 MB/s, which doubles the maximum burst rate of the Wide-Ultra SCSI.

Wide-Ultra2 SCSI Benefits

The Wide-Ultra2 SCSI LVD technology provides these additional benefits:

■80 MB/sec maximum burst

■Longer SCSI bus cable lengths

■System configuration for up to 15 peripherals

Wide-Ultra2 SCSI Compatibility

Wide-Ultra2 SCSI is compatible with your existing installed SCSI base. The Diff Sens circuit in the Wide-Ultra2 SCSI configures the drive operation and the appropriate bus capability. Wide-Ultra2 SCSI will work with the oldest SCSI designs. It is important to remember, however, that when using different SCSI devices on the same SCSI bus, all peripherals on that bus will respond to the earliest version SCSI specification. If an Ultra design is installed on an Wide- Ultra2 SCSI (LVD) bus, all devices will respond at Ultra speeds.

Compaq Smart Array 3200 Controller Reference Guide