An interconnect ASIC on SGIs provides support for the XIO bus found on SGI ‘ccNUMA' designs, such as the Octane (IP30) and Origin (IP27 and IP35) families, as well as related systems such as Onyx 3xx and Tezro. XIO components are called ‘widgets' and contain either I/O devices, processors, or memory.
A XIO bus supports up to 16 widgets, but the existing designs only use up to 8.
Special ‘hub' widgets allow several XIO buses to be interconnected, expanding the capacity of a given system, and allowing complex multi-node systems to be built.
Xbow is a crossbar switch a many to many switch
Xbow between hub and PCI widgets
XBow in the midplane of Onyx2 and Orign 2000
XBow in a field of widgets
Octane XBow sits on the front plane
xbstat monitors an xbow in real time.
Command run on "Mickey" an Octane with 8Gb RAM:
xbstat -d /hw/node/xtalk/0/mon
Part of the hinv of that machine:
Location: /hw/node PM20 Board: barcode HRJ328 part 030-1356-001 rev J Location: /hw/node/xtalk/15 IP30 Board: barcode KJN377 part 030-1467-001 rev D Location: /hw/node/xtalk/15/pci/2 PWR.SPPLY.ER Board: barcode AAE9460440 part 060-0035-002 rev A FP1 Board: barcode 33094C part 030-0891-003 rev E Location: /hw/node/xtalk/13 XTALKPCI Board: barcode LKY520 part 030-0952-005 rev E Location: /hw/node/xtalk/12 MOT20 Board: barcode JKD288 part 030-1240-003 rev G