IBM DTTA-351010 - Deskstar 10.1 GB Hard Drive Specifications page 18

Max Maximum value measured on any one drive over the full range of the environmental and
voltage conditions. (See section on Environment and D.C. Power Requirement.)
The seek time is measured from the start of motion of the actuator until a reliable read or write operation
may be started. Reliable read or write implies that error correction/recovery is not employed to correct for
arrival problems. The Average Seek Time is measured as the weighted average of all possible seek combina-
tions.
W e i g h t e d A v e r a g e =
W h e r e :
m a x = M a x i m u m S e e k L e n g t h
n = S e e k L e n g t h ( 1 t o m a x )
T n . i n = I n w a r d m e a s u r e d s e e k t i m e f o r a n t r a c k s e e k
T n . o u t = O u t w a r d m e a s u r e d s e e k t i m e f o r a n t r a c k s e e k
3.3.2.2 Full Stroke Seek (Without Command Overhead, Including Settling)
Function
Read
Write
Figure 5. Full Stroke Seek Time
Full stroke seek is measured as the average of 1000 full stroke seeks with a random head switch from both
directions (inward and outward).
3.3.2.3 Head Switch Time (Head Skew)
Head Switch Time (Typical)
Figure 6. Head Switch Time
A head switch time is defined as the amount of time required by the fixed disk to complete seek the next
sequential track after reading the last sector in the current track.
The measurement method is given in 3.3.5, "Throughput" on page 13.
10
O E M Specifications for DTTA-3xxxxx
m a x
S U M ( m a x + 1 n ) ( T n . i n + T n . o u t )
n = 1
( m a x + 1 ) ( m a x )
DTTA-35xxxx
Typical
15.0 msec
16.0 msec
2.0 msec
Max
18.0 msec
19.0 msec
DTTA-37xxxx
1.8 msec