An interconnect ASIC on SGIs. The xbow driver 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.