From 1996 on an effort to improve the speed resulted in HIPPI-6400, which was later renamed to
GSN (for
Gigabyte System Network), but GSN saw little use due to competing standards and high cost. GSN has a full-duplex bandwidth of 6400 Mbit/s or 800 MB/s in each direction. GSN was developed by
Silicon Graphics and
Los Alamos National Laboratory. It uses a parallel interface for higher speeds. GSN copper cables (HIPPI-6400-PH) are limited to . Like HiPPI-800, GSN uses two separate simplex channels (one in each direction). Unlike HiPPI-800, they are combined in a single cable and connector. Each channel consists of 16 data lines, four control lines, one framing line and two clock lines, for a total of 23 lines, all of which are differential. The connectors (Berg Micropax 100) have 100 pins total, of which 92 (23×2×2) are used. Fiber-optic cables (HIPPI-6400-OPT) are limited to 1 km. It uses the same principal signals as the copper interface, but runs everything at twice the clock rate, which halves the number of data and control fibers. Each channel thus consists of 8 data fibers, two control fibers and one clock and framing fiber each. All 12 fibers of a channel are bundled in a single multi-fiber connector and cable. A full-duplex connection thus consists of two separate cables. ==See also==