Physical Dimensions; Seek Time; Multisegmented Cache Buffer - Seagate Medalist Pro Series Product Manual

Medalist Pro 2520/2160 Product Manual, Rev. C

1.4 Physical dimensions

The mounting dimensions are shown in Figure 6 on page 23.
Height, max
Width, max
Depth, max
Weight

1.5 Seek time

Seek value is the interval between the time the actuator begins to move
and the time the head has settled over the target track. Seek time is a
true statistical average of at least 10,000 measurements of seek time.
All measurements are taken under nominal conditions of temperature
and voltage with the drive mounted horizontally. The specifications in the
table below are defined as follows:
• Track-to-track seek time is the average of all possible single-track
seeks in both directions.
• Average seek time is measured by executing seeks in both directions
between random cylinders.
• Full-stroke seek time is half the time needed to seek from track 0 to
the maximum track and back to track 0.
Track-to-track Average/typical
seek time seek time
3.5 msec typ 11 msec seek
4.5 msec max 12 msec read
13 msec write
Note. Host overhead varies between systems and cannot be specified.
Drive internal overhead is measured by issuing a no-motion seek.
Overhead is typically less than 0.5 msec.

1.6 Multisegmented cache buffer

The Medalist Pro ST52520A and ST52160A drives are available with a
128-Kbyte, multisegmented cache buffer that improves performance by
reducing access times.
Read look-ahead. The drive uses the read segments to store additional
logical sectors, after the last requested sector, into a buffer before the
computer requests the additional sectors. The cache buffer stores data
0.748 inch (19 mm)
4.01 inches (101.8 mm)
5.38 inches (136.6 mm)
1.0 lb (0.45 Kg)
Full-stroke
seek time
25 msec typ
27 msec max
7
Average
latency
5.58 msec