Hitachi HUS154530VLF400 User Manual

                   

Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification

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The disconnect/reconnect page provides the Initiator with the means to tune the performance of the Fibre Channel Loop.

The drive uses the disconnect/reconnect parameters to control when it attempts to regain control of the Loop during READ 
and WRITE commands.

• Read Buffer Full Ratio is the numerator of a fraction whose denominator is 256. The fraction indicates how full the 

drive data buffer should be before attempting to re-arbitrate for the Loop.  If the ratio is set to 0h, the target will cal-
culate and use an optimal ratio based on the negotiated transfer rate.

• Write Buffer Empty Ratio is the numerator of a fraction whose denominator is 256. The fraction indicates how empty 

the drive data buffer should be before attempting to re-arbitrate for the Loop.  If the ratio is set to 0h, the target will 
calculate and use an optimal ratio based on the negotiated transfer rate.

Both the Read Buffer Full Ratio and the Write Buffer Empty Ratio pertain to the current active notch. For each active notch as 
defined in page 0Ch there are separate Read Buffer Full Ratios and Write Buffer Empty Ratios. When the active notch is set to 
zero, the values are applied in mode page 0Ch across all notches.

• Maximum Burst Size is not supported, and any value in this field is ignored.