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Dell 3 User Manual

Page 73

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PERC 3/DC and PERC 3/DCL Features

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SCSI Connectors

The PERC 3/DC and PERC 3/DCL adapter has two types of SCSI
connectors:

• Two 68-pin high density internal connectors
• Two 68-pin external ultra-high-density connectors

Only one connector type can be used for the SCSI channel at any one time.

SCSI Termination

PERC 3/DC and PERC 3/DCL uses active termination on the SCSI bus
conforming to SCSI-2 and SCSI-3 specifications. Termination
enable/disable is automatic through cable detection.

SCSI Firmware

The PERC 3/DC and PERC 3/DCL firmware handles all RAID and SCSI
command processing and supports the feature listed in Table 5-8.

Ta b l e 5 - 8 . S C S I F i r m w a r e

Feature

Description

Disconnect/

reconnect

Optimizes SCSI bus seek.

Tagged command

queuing

Multiple tags to improve random access

Scatter/gather

A single command can transfer data to and from different

memory locations.

Multi-threading

Up to 255 simultaneous commands with elevator sorting

and concatenation of requests per SCSI channel

Stripe size

Variable for all logical drives: 2 KB, 4 KB, 8 KB, 16 KB,

32 KB, 64 KB, or 128 KB

Rebuild

Multiple rebuilds and consistency checks with user-

definable priority