16
DiamondMax 21 Serial ATA Product Manual, Rev. A
2.6 Seek time
Seek measurements are taken with nominal power at 25 °C amb ient t emperature. All times are measured using
drive diagnostics. The specifications in the table below are defined as follows:
Track-to-track seek time is an average of all possible single-track seeks in both directions.
Average seek time is a true statistical random average of at least 5,000 measurements of seeks between
random tracks, less overhead.
*Measured in performance mode.
**Measured in quiet mode.
Note. These drives are designed to consistently meet the seek t imes r epresented in this manual. Physical
seeks, regardless of mode (such as track-to-track and average), are expected to meet the noted
values. However, due to the manner in which these drives are formatted, benchmark tests that
include command overhead or measure logical seeks may produce results that vary from these
specifications.
2.7 Start/stop times2.8 Power specification s
The drive receives DC power (+5V or +12V) throu gh a native SATA power connect or. See Figure 4 on page 28.
2.8.1 Power consumption
Power requirements for the drives are listed in the table on page 9. T ypi cal powe r measu rem ent s are ba sed on
an average of drives tested, under nominal conditions, using 5.0V and 12.0V input voltage at 25°C ambient
temperature.
Spinup power
Spinup power is measured from the time of power-on to the time that the drive spindle reaches operating
speed.
Seek mode
During seek mode, the read/write actuator arm moves toward a specific position on the disc surface and
does not execute a read or write operation. Servo electronics are active. Seek mode power represents the
worst-case power consumption, using only random seeks with read or write latency time. This mode is not
typical and is provided for worst-case information.
Read/write power and current
Read/write power is measured with the heads on track, based on a 16-sector write followed by a 32-msec
delay, then a 16-sector read followed by a 32-msec delay.
200 - 320 GB models* 40 - 80 GB models**
Typical seek times (msec) Read Write Read Write
Track-to-track <0.8 <1.0 <0.8 <1.0
Average <8.5 <10.0 <11.0 <12.0
Average latency: 4.16 4.16 4.16 4.16
Power-on to Ready (sec) 15 (max)
Standby to Ready (sec) 15 (m ax)
Ready to spindle stop (sec) 10 (max)