Seagate BARRACUDA2 - Manual (Page 27)

ST12450W/WD Installation Guide, Rev. B 25
Synchronizing spindles
in multiple drive configurations
If you are installing two or more Barracuda drives, you
may (optionally) want to synchronize their spindles to
reduce the latency associated with switching from one
drive to another.
Spindle sync cables are used to connect the drives.
Use pins 11 and 12 on the J5 connector to attach the
spindle sync cable. Pin 11 provides the reference index
signal (REFSIG+) and pin 12 provides ground (GND).
See Figure 7.
Spindle sync reference index signal
(REFSIG+).
Spindle Sync Cable Connector (SSC)
These pins are used to connect a
spindle sync cable.
Ground (GND).
SSC
J5
DC Power
Connector
SCSI I/O
Connector
J5
Pin 1
Figure 7. Spindle sync jumpers and connectors