Silicon Graphics Inc expects that within a year, companies will be using GSN Gigabit System Network technologies to move very large amounts of data between clustered systems or around a network in real-time. Entertainment and post production companies with uncompressed high-definition TV movies, and content and enterprise data warehousing applications are potential uses for the next-generation local area network technology which establishes two data channels providing up to 6400 Gbps bandwidth in each direction. Up to six times faster than Gigabit Ethernet or Fiber Channel, GSN and cheaper per megabyte than Fast Ethernet, FDDI or ATM, GSN is nevertheless likely to remain a solution for technical computing users for the near-term as GSN network interface cards, switches, hubs and routers will remain expensive, partly because of the bandwidth they require. GSN’s potential however, is enormous, as its high bandwidth – it will shift data at 25Gbps by 2000 – and very low latency – between one and five microseconds – makes it suitable for use in many types of connections; clustering, I/O, backplane and buses. GSN is the marketing name a group of vendors supporting the technology have chosen for what is actually a second generation of the 800Mbps HIPPI high-performance parallel interface originally developed Cray Research and now an IEEE standard called HIPPI-6400, or Super-HIPPI. Moreover SGI is now offering a Super-HIPPI media access control chipset dubbed SuMAC for companies that are building GSN devices, and is expected to shortly unveil a strategy for plumbing its computers with GSN. SGI will be the only vendor selling GSN adapters in the near- term, though even its product isn’t going to be around until the first quarter of next year. SGI’s Cache coherency will have to be built on top of GSN where required. Other vendors, including HP, IBM and DEC which each demonstrated GSN running on their systems at last year’s Supercomputing show in San Jose, are also expected to support GSN in future products. Copper wire connections are supported over 50 meters – 1 kilometer distances over fiber. Essential Communications Inc is already using SuMAC in a GSN switch it is offering to early adopters of the technology, though production versions won’t be available until mid-1999. GSN supports IP traffic – though SGI says the forthcoming IP 6.0 implementation will work best with it – as well as the higher- level ANSI ST scheduled transfer high-bandwidth protocol that has been stripped from HIPPI and is being added to Ethernet for use with the Intel Corp-driven Virtual Interface Architecture for clustering computing nodes, and will also support ATM and GSN itself. There’s currently a spat between Hewlett-Packard Co and other GSN players over ST, to which HP claims patent rights. At a recent meeting of an IEEE HIPPI group it was thought likely a bargain will be struck where HP will turn over its patent claims in return for rights to SGI’s SuMAC work. Although GSN won’t replace use of the forthcoming Gigabit Ethernet protocols in general purpose LANs, GSN’s advantage is that it requires minimal use of the host operating system and CPU and is therefore has an important application for compute-intensive environments. But even next-generation 66MHz PCI bus with an available 4Gbps bandwidth will be able to take advantage of it by clustering say, multiple eight-way Intel SMP servers. SGI says GSN’s importance depends upon the market space. For Gigabit Ethernet it is a big deal, but for certain applications, such as those described above, GSN it, SGI exclaims. SGI is using GSN as part of the work it’s doing under the US Department of Energy’s Advanced Strategic Computing Initiative (CI No 3,341). SGI’s challenge is whether it can turn its technical lead – SuMAC chips will be used in all GSN devices and SGI says it’s the only company building them – into a marketing success. We’re supposed to be hearing from SGI in a few weeks’ time.
