Path: utzoo!attcan!utgpu!news-server.csri.toronto.edu!rutgers!uwm.edu!rpi!zaphod.mps.ohio-state.edu!lavaca.uh.edu!menudo.uh.edu!lobster!siswat!buck From: buck@siswat.UUCP (A. Lester Buck) Newsgroups: comp.periphs.scsi Subject: Re: Diff. between SCSI I & II Message-ID: <561@siswat.UUCP> Date: 6 Oct 90 14:18:41 GMT References: <1990Oct4.003204.20738@idt.unit.no> Organization: Photon Graphics, Houston Lines: 21 In article , ben@epmooch.UUCP (Rev. Ben A. Mesander) writes: > >What is the teorethical throughput? > > Well, ethically speaking, that depends on another "or what". There are > several options for SCSI-2, including something called "fast SCSI", and > the 16 and 32 bit data paths. I can't remember the exact numbers right > now, and I'm too sleepy to dig into my SCSI-2 manual. Suffice to say > that the maximum throughput is a lot faster than real-world disk drives > can sustain. If I remember, fast wide SCSI-2 is 40 MB/sec, with 10 M transfers/sec on a 4 byte wide bus. But this is somewhat slow in the current world of fast disks. There have been parallel transfer disks for some time time that gang all the heads together for 20-40 MB/sec. The new disk arrays being marketed by Maximum Strategies, for example, transfer at something really gross like 120 MB/sec and layer IPI-3 on HPPI packets. I think they use two HPPI channels to handle the peak rate. Ciprico had the first SCSI-2 controller on the market and its purpose was to run a RAID array. -- A. Lester Buck buck@siswat.lonestar.org ...!uhnix1!lobster!siswat!buck