Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!purdue!gatech!mcnc!ecsvax!dukeac!wolves!ggw From: ggw@wolves.uucp (Gregory G. Woodbury) Newsgroups: comp.arch Subject: Re: PC vs. mainframe I/O (Re: SCSI on steroids) Summary: I want a fast bus! Message-ID: <1989Sep12.031453.22947@wolves.uucp> Date: 12 Sep 89 03:14:53 GMT References: <21962@cup.portal.com> Reply-To: ggw@wolves.UUCP (Gregory G. Woodbury) Organization: Wolves Den UNIX BBS Lines: 71 In article <21962@cup.portal.com> cliffhanger@cup.portal.com (Cliff C Heyer) writes: >Now, on the subject of PCs and disk I/O... : >What *will* change this though is the emergence of >new low cost chips such as the NCR53C700 SCSI >chip, and the fall in price of SRAM or faster DRAM >(actually *vastly* faster DRAM) When the PC makers >can use low cost chips for high bandwidth rather >than engineer their own bus design, they will do >it. They will be able to put ESDI/SCSI interfaces >ON the motherboard and BYPASS the AT bus. : : >And since the market is NOT demanding a fast PC >bus, why go to all the trouble? Maybe you'll loose >money. If you do put a fast bus together, you'll >point it towards the workstation market where the >profit margins will support the engineering costs. So what in the hell is a "workstation"? I have been unable to make any real distinction between a "workstation" and a "high-performance PC". The distinction (if there is one) is purely marketing hype. We are/have been replacing our dependency on mainframe computing by acquiring a network of dedicated, "high performance" (and relatively) low cost "PC's". Some of these things are "workstations", but they all use the AT style PC buss, and take too bloody long to do the disk i/o. It is cheaper (more effective) for us to have an Intergraph Clipper chipset mounted in an AT-class PC take 8 hours to run our application than to have an IBM-3081K do it in 3 and then send us back the results. With the batch environment set-up and post-processing overhead, we get better throughput from the local PC's. What's more, given the typical restrictions placed on jobs in botched (pun intended) mainframe environments, we can deal with bigger memory sizes (with no change in cost) on the "PC's" Here are some real numbers: an 88000 based co-processor in a '386 33 MHz PC with 1.2 GBytes of disk and 24 MB of memory can cost ~$30,000. This is amortizable over several years. The full cost recovery for this pc/workstation (assuming 40 hr weeks!) is < $6.00/hour! The University owned (consortium) mainframe limits normal jobs to 5.5MB of memory and costs >$150.00/hour! Our application benchmark took ~1 hour to run on the 3081. It takes about 1.8 hours to run on the 88000, and costs a hell of a lot less 'cause there isn't a memory premium overhead on the cost! If I could have this processor (88000) in a machine with a decently fast bus AND at a cost nearly the same, then it would be perfect. But once you get away from the AT-bus and such, the costs get unreasonable. We priced a NS32532 in an AT-bus card (co-processor) and an NS32532 in a VME bus box. Holding all other things equal/equivalent, the VME bus based box would have cost us THREE times the cost of the co-processor configuration! I like reading the architecture group here, it just gets so frustrating when I hear the technical people waxing estatic about there latest new toy and not realizing that just behind their "cutting edge" of research and development there is the "bleeding edge" of people trying to use this stuff in a reasonable (and cost-efficient!) manner. -- Gregory G. Woodbury Sysop/owner Wolves Den UNIX BBS, Durham NC UUCP: ...dukcds!wolves!ggw ...dukeac!wolves!ggw [use the maps!] Domain: ggw@cds.duke.edu ggw@ac.duke.edu ggw%wolves@ac.duke.edu Phone: +1 919 493 1998 (Home) +1 919 684 6126 (Work) [The line eater is a boojum snark! ] -- Gregory G. Woodbury Sysop/owner Wolves Den UNIX BBS, Durham NC UUCP: ...dukcds!wolves!ggw ...dukeac!wolves!ggw [use the maps!] Domain: ggw@cds.duke.edu ggw@ac.duke.edu ggw%wolves@ac.duke.edu Phone: +1 919 493 1998 (Home) +1 919 684 6126 (Work) [The line eater is a boojum snark! ]