Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 8/7/84; site ucbvax.ARPA Path: utzoo!watmath!clyde!burl!ulysses!cbosgd!ucbvax!info-vax From: info-vax@ucbvax.ARPA Newsgroups: fa.info-vax Subject: Re: 8600 performance? Message-ID: <3245@ucbvax.ARPA> Date: Tue, 13-Nov-84 09:32:42 EST Article-I.D.: ucbvax.3245 Posted: Tue Nov 13 09:32:42 1984 Date-Received: Wed, 14-Nov-84 05:25:07 EST Sender: daemon@ucbvax.ARPA Organization: University of California at Berkeley Lines: 28 From: Richard Garland Unibus HSC50 and DSA disks Its true the HSC50 has a PDP11 in it (F11 chip set) but there is no Unibus or UDA50's in it. It has a fast backplane into which disk controllers and a CI interconnect plug. The PDP11 is the supervisor of the whole thing but data does not pass through it. The HSC should handle multple controllers and multiple disks in parallel and fill up the band width of the CI in a reasonable fashion. The Unibus connections via the UDA50 is clearly the low end solution whereas DEC intends to push the CI for upper end systems. We find that a UDA50, Ethernet, 56 terminals, an E&S PS330, and an FPS AP164 can all coexist on our one Unibus nicely. Just takes some intellegent buffering and queueinmg in the CPU which VMS manages adequately. Certainly if we had the funds we would look ata second Unibus or a CI. If (when) we get an 8600 a CI will obviously be part of it. My feeling is that with Unix one is not wedded to DSA disks particularly or to clusters so there Emulex/Fuji etc make more competitive sense. Being a VMS shop on the other hand I see value in staying with the DSA disks and looking forward to clusters some day. Rg -------