Path: utzoo!attcan!uunet!wuarchive!brutus.cs.uiuc.edu!apple!amdahl!sbf10
From: sbf10@uts.amdahl.com (Samuel Fuller)
Newsgroups: comp.arch
Subject: Re: SCSI on steroids, mainframes move over
Message-ID: <56FO02qB4e0k01@amdahl.uts.amdahl.com>
Date: 24 Aug 89 23:50:04 GMT
References: <5932@pt.cs.cmu.edu> <5962@pt.cs.cmu.edu>
Reply-To: sbf10@amdahl.uts.amdahl.com (Samuel Fuller)
Organization: Amdahl Corporation, Sunnyvale CA
Lines: 58

In article <5962@pt.cs.cmu.edu> butcher@g.gp.cs.cmu.edu (Lawrence Butcher) writes:
>For my education, could a couple of readers give me info about
     >--anyone who is interested
>systems you are familiar with?  Mainframes or supercomputers ok.
>Here are some questions whose answers I do not know:

All numbers are for Amdahl 5990-1400
>How many disk interfaces does a typical mainframe have?
128 Maximum (Channels)
>How many drives per interface?
4 Maximum (I/O Interface per channel)
>How big is the average drive?
3380 class drives hold 1.8GBytes
>What is the max speed of the connection from disk interface to memory?
4.5 MB/sec
>How many transfers can happen at once?
128 (All channels can simultaneously transfer data at their max rate)
>What is a typical short term I/O rate sustained over a period of a 30 seconds?
No data
>What is a typical long term I/O rate sustained over a period of several hours?
No data
>What percentage of real memory bandwidth does the I/O system get?
No data
>What is an estimate of processor mips, to give MByte/sec / Mips?
105 CISC Mips for 4 processor model
>What are better questions?
How much DASD does a mainframe support?

Average sites will have several hundred 3380 devices, meaning the average
mainframe DASD farm will be in the several hundred gigabyte range.

Additional Comments:

Although mainframes haven't made the startling performance gains that
microshave over the past few years.  They are still advancing in both
technology and performance.

I was just looking over some of the sales literature for our processors
and was surprised by the speed of the devices.

Expanded Storage is 2GBytes of 120-ns DRAM
Main memory is 512MBytes of 55-ns SRAM
Cache is implemented with 2.8ns ECL
Cycle time is 10ns

The CPU is built from 336 ECL chips on a double-sided 42-layer
water-cooled printed circuit board.(It's pipelined too!)
No wonder the machines cost $10 Million.
-- 
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Sam Fuller / Amdahl System Performance Architecture

I speak for myself, from the brown hills of San Jose.

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