Xref: utzoo comp.arch:11610 comp.databases:3772 Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!gem.mps.ohio-state.edu!tut.cis.ohio-state.edu!ucbvax!mtxinu!rtech!daveb From: daveb@rtech.rtech.com (Dave Brower) Newsgroups: comp.arch,comp.databases Subject: Re: *big iron* Message-ID: <3752@rtech.rtech.com> Date: 3 Oct 89 05:06:18 GMT References: <21962@cup.portal.com> <1989Sep12.031453.22947@wolves.uucp> <22130@cup.portal.com> <1989Sep16.044013.429@wolves.uucp> <259@ssp1.idca.tds.philips.nl> <22308@cup.portal.com> <7981@cbmvax.UUCP> <11538@burdvax.PRC.Unisys.COM> <22488@cup.portal.com> <24950@lou Reply-To: daveb@rtech.UUCP (Dave Brower) Organization: Relational Technology Inc, Alameda CA Lines: 21 some people wrote: >>Cray DD-40 disk drives can support >10MB/sec through the operating >>system (at least COS; I assume the case is also true for UNICOS). > >This brings up a point: in what processing regimes does total >sustained disk tranfer rate be the performance-limiting factor? > In many tp/database/business applications, CPU is fast enough that disk bandwidth will soon be the limiting factor for many applications. Some airline reservation systems are said to have huge farms of disk where only one or two tracks are used on the whole pack to avoid seeks, for instance. A 1000 tp/s database benchmark might easily require 10MB/sec i/o throughput. Maybe Cray should change markets... -dB -- "Did you know that 'gullible' isn't in the dictionary?" {amdahl, cbosgd, mtxinu, ptsfa, sun}!rtech!daveb daveb@rtech.uucp