IBM DTTA-351010 - Deskstar 10.1 GB Hard Drive, Технические характеристики, Страница: 21 / 188

3.3.5 Throughput
3.3.5.1 Simple Sequential Access
Figure 12. Simple Sequential Access Performance
| The above table gives the time required to read for a total of 8000x consecutive blocks (16,777,216 bytes)
| accessed by 128 read commands. Typical and Max values are given by 105% and 110% of T respectively
throughout following performance description.
Note: Assumes a host system responds instantaneously and host data transfer is faster than sustained data
rate.
|
T = A + B + C + 1 6 , 7 7 7 , 2 1 6 / D + 5 1 2 / E + D R Q
w h e r e :
T = C a l c u l a t e d T i m e ( s e c )
A = C o m m a n d P r o c e s s T i m e
( C o m m a n d o v e r h e a d ) ( s e c )
B = A v e r a g e S e e k T i m e ( s e c )
C = A v e r a g e L a t e n c y ( s e c )
D = S u s t a i n e d D i s k
Ä
B u f f e r T r a n s f e r R a t e ( b y t e / s e c )
E = B u f f e r
Ä
H o s t T r a n s f e r R a t e ( b y t e / s e c )
D R Q = D a t a R e Q u e s t i n t e r v a l ( s e c )
3.3.5.2 Random Access
| The above table gives the time required to execute a total of 1000x read commands which access a random
LBA.
|
T = ( A + B + C + 5 1 2 / D + 5 1 2 / E + D R Q ) * 4 0 9 6
w h e r e :
T = C a l c u l a t e d T i m e ( s e c )
A = C o m m a n d P r o c e s s T i m e
( C o m m a n d o v e r h e a d ) ( s e c )
B = A v e r a g e S e e k T i m e ( s e c )
C = L a t e n c y ( s e c )
D = A v e r a g e S u s t a i n e d D i s k
Ä
B u f f e r T r a n s f e r R a t e ( b y t e / s e c )
E = B u f f e r
Ä
H o s t T r a n s f e r R a t e ( b y t e / s e c )
D R Q = D a t a R e Q u e s t i n t e r v a l ( s e c )
Operation DTTA-35xxxx
typical / max.
DTTA-37xxxx
typical / max.
Sequential Read (Zone 0) 1.4 sec / 1.5 sec 1.3 sec / 1.4 sec
Sequential Read (Zone 7) 2.6 sec / 2.7 sec 2.2 sec / 2.3 sec
Operation DTTA-35xxxx DTTA-37xxxx
Random Read ( typical / max ) 63 sec / 66 sec 58 sec / 60 sec
Drive Characteristics
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