Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!pt.cs.cmu.edu!gandalf.cs.cmu.edu!lindsay From: lindsay@gandalf.cs.cmu.edu (Donald Lindsay) Newsgroups: comp.arch Subject: Re: IO buses Keywords: SCSI Message-ID: <11357@pt.cs.cmu.edu> Date: 11 Dec 90 15:47:43 GMT References: Organization: Carnegie Mellon Computer Science, or maybe Robotics Institute Lines: 18 In article pcg@cs.aber.ac.uk (Piercarlo Grandi) writes: >As an IO bus the ISA bus and Unibus and QBUS are >perfectly adequate for the most common minicomputer applications. After >all the fastest IO buses commonly available (IPI etc. are *expensive*) >do not get much over 1-2MB/sec., and the ISA bus runs to 5-6MB/sec. You >can have multiple SCSI adapters on an ISA bus and you dont' saturate it. I seem to recall a typical loaded Unibus getting rather under 1 MB/s. The same for Ethernet, come to think of it. The inadequacy of the current situation is demonstrated by the Creo optical drive, which puts a terabyte on a single reel. With its 3 MB/s SCSI interface, it takes **four days** to read one tape! [In Creo's defence, they have a fast scan mode.] -- Don D.C.Lindsay .. temporarily at Carnegie Mellon