Graphcore IPU-POD128, Build And Test Manual, Page: 46 / 113

IPU-POD128 build and test guide
3.6.6 IPU-M2000 to ToR switch cabling (QSFP)
The next step is to connect the IPU-M2000s to the ToR switch. There are two RNIC ports on the left side of each
IPU-M2000, as shown in Fig. 3.51 . Only one of them should be connected from each IPU-M2000 to the ToR
switch with either the 1m or 1.5m QSFP cables supplied.
Fig. 3.51: IPU-M2000 RNIC ports (QSFP)
In order to manage the cables, the QSFP cables are divided into two different lengths:
• 8x QSFP 1.0m from IPU-M2000 #9-16 to ToR switch ports 16 to 9
• 8x QSFP1.5m from IPU-M2000 #1-8 to ToR switch ports 17 to 24
Start from port 9 on the ToR switch and connect the cable to port 2 of IPU-M2000 #16.
Continue cabling from ports 10 to 24 on the ToR switch to port 2 on IPU-M2000 #15 to IPU-M2000 #1 respec-
tively.
Dress the cables down the side of the cabinet. A set of four cables can be looped into cut-outs on the side of the
cabinet. Tie the bundle together at the top with a Velcro strip as shown in Fig. 3.52 .
Fig. 3.52: IPU-M2000 to ToR switch cabling
The IPU-M2000s should be connected to the ToR switch as given in Table 3.7 , note that the IPU-M2000s are
numbered from bottom to top #1 to #16.
Version: latest (2021-11-25) 42