Что означает "low RPM at standby"?

Low RPM
When longer periods of non use occur, additional power savings is possible. In this mode,
in addition to head unload from the media, the spindle motor can be slowed to a lower
spin rate (approximately 60% of normal). This action further reduces the power needed for
the drive, 27% less than the unload mode. In less than seven seconds, the drive can be
restored to ready mode for data access.
Standby

One final mode enables the greatest power saving state. In this case, as above, the
heads are moved to the ramp. In standby mode, power is removed from the disks.
Stopping the disks results in 38% savings over the Low RPM mode, or a huge 87% less
than when online.
The standby drive can be quickly brought to the online mode, if for example, one of the
active drives is removed from the system. This mode is especially useful in RAID
environments where one drive serves as a spare.
Each of the four modes can be enabled via the Set Feature commands. They are
described in more detail in the Advanced Power Management section of the Deskstar
Hard Disk Drive Specification.
Power with control