The charts below are an attempt to allow the different IOAs available to be compared on a single
chart. An I/O Intensive Workload was used for our throughput measurements. The system used
was a 520 model with a single 5094 attached which contained the IOAs for the measurements.
Note: the 5709 and 573D are cache cards for the built in IOA in the 520/550/570 CECs, even
though I show them in the following chart like they are the IOA. The 5709 had 8 - 15K 35GB
DASD units and the 573D had 8 - 15K 70 GB DASD, the maximum DASD allowed on the built
in IOAs.
The other IOAs used 10 - 15K 35GB DASD units. Again this is all for relative comparison
purposes as the 571B only supports 10 DASD units in a 5094 enclosure and a maximum of 12
DASD units in a 5095 enclosure. The 2757 and 2780 can support up to 18 DASD units with the
same performance characteristics as they display with the 10 DASD units, so when you are
considering the right IOA for your environment remember to take into account your capacity
needs along with this performance information.
14.1.4.3
14.1.4.4
IBM i 6.1 Performance Capabilities Reference - January/April/October 2008
©
Copyright IBM Corp. 2008
Chapter 14 DASD Performance
196
0
0.1
0.2
0.3
0.4
0
1000
2000
3000
4000
5000
571B RAID-5 IOP
571B RAID-5 IOPLess
571B RAID-6
5709 RAID-5
573D RAID-5
5703 RAID-5
2780 RAID-5
Workload Throughput
S
yst
e
m
R
e
sp
o
n
s
e
T
ime
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s
e
c
)
0
10
20
30
40
50
0
200
400
600
800
1000
1200
1400
571B RAID-5 IOP
571B RAID-5 IOPLess
571B RAID-6
5709 RAID-5
573D RAID-5
5703 RAID-5
2780 RAID-5
Ops/Sec
D
A
S
D
R
e
s
pons
e
Ti
m
e
(
m
s
)