Technical information

HGST Ultrastar C15K600 Hard Disk Drive Specification
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but before writing it to the media. When WCE = 1, the drive operates as if AWRE = 1.
Note: When WCE = 1, a SYNCHRONIZE CACHE command must be done to ensure data are written to the media
before powering down the Target.
- MF (Multiplication Factor) bit determines how the Maximum and Minimum Pre-fetch parameters are interpreted.
If this bit is set to zero, the parameters are used as is. If the bit is set to one, the parameters are multiplied by the
number of blocks requested in the Read Command.
- RCD (Read Cache Disable) bit set at zero indicates that the drive may return some or all of the data requested
by a READ (6) or READ (10) command by accessing the data buffer, not the media. An RCD bit set at one
indicates that the Target does not return any of the data requested by a READ (6) or READ (10) command by
accessing the data buffer. All of the data requested is read from the media instead.
- Demand Read Retention Priority is not supported.
- Write Retention Priority is not supported.
- Disable Pre-fetch Transfer Length is used to prevent read-ahead after Read commands that are longer than
the specified number of blocks. If this parameter is set to zero, a read-ahead is not performed.
- Minimum Pre-fetch specifies the minimum number of LBAs that the drive should after each READ command.
A value of zero indicates that read ahead should be terminated immediately after a new command arrives,
except when the new command is on the current head and track.
- Maximum Pre-fetch specifies the maximum number of LBAs to read ahead after a Read command.
- Maximum Pre-fetch Ceiling specifies the maximum number of blocks the drive should attempt to read ahead.
This field is ignored.
- FSW (Force Sequential Write) is not supported and is ignored. All logical blocks will be written in sequential
order.
- LBCSS (Logical Block Cache Segment Size) bit when set to one indicates that the Cache Segment Size field
units shall be interpreted as logical blocks. When it is set to zero, the Cache Segment Size field units shall be
interpreted as bytes.
- DRA (Disable Read Ahead) bit when set to one request that the Target not read into the buffer any logical block
beyond the addressed logical block(s). When it is set at zero, the Target may continue to read logical blocks into
the buffer beyond the addressed logical block(s).
- Number of Cache Segments field is used to select the number of data buffer cache segments. This parameter
is valid only when the SIZE bit is set at zero. It is ignored when SIZE is set at one.
- Cache Segment Size field indicates the requested segment size in Bytes or Blocks, depending upon the value
of the LBCSS bit. The Cache Segment Size field is valid only when the SIZE bit is one. It is ignored when SIZE
is set at zero.
- Non Cache Segment Size is not supported and is ignored.