Myrinet System Interconnect Guide

Figure 3-4: Block Diagram of the gigabit ethernet switch card
15 14 13 12 11 10 9 8
7 6 5 4
3 2 1 0
Myrinet Backplane Interface
Serial link
Lanai-XM-based Myrinet-GbE conversion for each of these 8 ports
Clocks
Sense &
Control
Scan path
XBar16
GbE Front-panel Ports
Power & hot-swap
circuits
dual + 12V
HPTC-0017
XBar16
The X Bar16 is a 16-port crossbar switch impl emented in a single chip. The fat tree
topology provides s ystematic ways of connecting these 16-port crossbar switches to
serve large numbe rs of hosts in a way tha t achiev es full bisection .
3.2 Spine card
A spine card looks the same as an 8-port switch card, except the front-panel
ports are labeled 0–7, corresponding to the p orts of the backplane interface. The
indicator LEDs are the same. These cards are used in modular configurations
(more than 128 nodes). They do not have an XBar16.
Switch, spine and monitoring line cards 3-3