Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!brutus.cs.uiuc.edu!jarthur!bridge2!mips!ultra!casey From: casey@ultra.com (Casey Cox) Newsgroups: comp.arch Subject: Re: bus on new IBMs Message-ID: <1990Feb26.185737.9409@ultra.com> Date: 26 Feb 90 18:57:37 GMT References: Reply-To: casey@ultra.com (Casey Cox) Organization: Ultra Network Technologies Lines: 19 In article Robert.Sansom@CS.CMU.EDU writes: >Excerpts from mail: 23-Feb-90 bus on new IBMs Wm. Scott `. Draves@cs.b >(446) >> I read in Unix Today! that the new IBM RISCs used an improved MCA bus >> that doubled its performance from 20Mb/s to 40Mb/s. There is a >> separate, higher performance, bus for memory. > >Shouldn't that be 20-40 MB/s (peak). > The new IBM RISCs have a new micro channel bus that supports the extended streaming protocol that allows data to be transferred every 100ns. This new 40 MB/sec is of course their peak transfer rate and I'm sure the sustained rate is somewhat lower, but it has nothing to do with the old 20 MB/sec rate on other machines without the streaming protocol. -- Casey Cox Ultra Network Technologies / 101 Daggett Drive / San Jose CA 95134 casey@ultra.com ...!ames!ultra!casey (408) 922-0100