IBM Switch 9077 - Manual (Page 233)

Multiple RS/6000 SPs and Multiple GRFs 215
Performance:
To get a rough overview of the data transfer rates that can be achieved in this
scenario, the following test was performed:
1. We used ftp to conduct several file transfers of a 300 MB file from the
nodes in SP2 to one chosen node in SP21, and at the same time used ftp
to conduct several file transfers of a 300 MB file from the nodes in SP21 to
a chosen node in SP2. We sent the files to /dev/null on the receiving node
to eliminate any hard disk influence.
We saw up to about 14.5 MB/s with just one side sending data; with all
nodes sending and receiving, we achieved an duplex throughput of about
24 MB/s on the ATM port.
So it just might turn out that one 155 Mbit ATM port is not enough for a
performance connection between two SP systems.
7.1.2 ATM OC-3c Backbone - Using Two Ports
This setup is basically the same as using just one port of the ATM card, as
described in Section 7.1.1, “ATM OC-3c Backbone - Using One Port” on page
210. To avoid the difficulties regarding the need of different (sub)networks on
the two ports, we decided to use the GRF bridging implementation as
described in
GRF Configuration Guide 1.4, GA22-7366. See Figure 69 and
Table 24 on page 216 for the illustration of the new scenario.
Figure 69. SP Switch - ATM Bridged - SP Switch Connection
SP
Switch
Router 1
GRF 400
SP Switch Router
Adapter card 1
SP Switch 1
SP2
SP processor node
SP processor node
IP 192.168.13.4
Mask 255.255.255.0
Mask 255.255.255.0
Net 192.168.13.0
SP
Switch
Router 2
GRF 1600
SP Switch Router
Adapter card 2
SP Switch 2
SP21
SP processor node
SP processor node
IP 192.168.14.4
Mask 255.255.255.0
Net 192.168.14.0
ATM OC-3c
Adapter card
ATM OC-3c
Adapter card
Net 10.1.1.2
Net 10.1.1.1