14.3.2 57B8/57B7 IOA
With the addition of the POWER6 520 and 550 systems comes the new 57B8/57B7 SAS Raid
Ennoblement Controller with Auxiliary Write Cache. This controller is only available in the
POWER6 520 and 550 systems and provides RAID5/6 capabilities, with 175MB redundant write
cache. Below are some charts comparing the Storage Controllers for the POWER5 570 (573D),
which can be either mirrored or RAID5 protected. The POWER6 570 (572C) which can only be
mirrored, and the POWER6 520/550 (57B8/57B7) which can be RAID5/6 or protected with
mirroring.
IBM i 6.1 Performance Capabilities Reference - January/April/October 2008
©
Copyright IBM Corp. 2008
Chapter 14 DASD Performance
210
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
100
350
600
850
1100
1350
1600
1850
V5R4M5 9406 570 573D 6 DASD Mirrored (No Cache)
V6R1M0 9406 MMA 572C 6 DASD Mirrored (No Cache)
V6R1M0 9406 57B8 6 DASD Mirrored (Cache)
V6R1M0 9406 57B8 6 DASD RAID5 (Cache)
Workload Throughput
S
y
s
tem
R
e
s
pon
s
e
T
im
e
(
s
ec
)
0
5
10
15
20
25
30
35
40
0
400
800
1,200
1,600
V5R4M5 9406 570 573D 6 DASD Mirrored (No Cache)
V6R1M0 9406 MMA 572C 6 DASD Mirrored (No Cache)
V6R1M0 9406 57B8 6 DASD Mirrored (Cache)
V6R1M0 9406 57B8 6 DASD RAID5 (Cache)
Ops/Sec
D
ASD
R
e
s
p
o
n
s
e
T
im
e
(m
s
)