🚀 go-pugleaf

steve wolfe wrote:

> Douglas W. Jones,201H MLH,3193350740,3193382879 wrote:
> >
> > From article <33B8C6...@pce.net>, by Micheal Peters
> <mich...@pce.net>:
> > > Rashid J Al-Ali wrote:
> > >>
> > >> I am wondering, why people would use Mainframe computers.?
> > >> What are the major reasons for using mainframes.?
> > >> And what are the type of applications that mainframe would be
> used for?
> > >
> > > Well up untill recently Mainframes could crunch large formuls and
> > > numbers faster and more percice (gerr.. Missing my spell checker).
>
> >
> > Nah.  A DEC Alpha is still the fastest single CPU on the market, and
>
> > mainframe CPU speed hasn't had much of an edge on microprocessor CPU
>
> > speed since the mid 1980's.
> >
> > Where mainframes really win is in massive I/O bandwidth.  If you
> want
> > multimedia servers, with huge disk farms and massive network
> bandwidth,
> > a mainframe may serve you better than the competition.  Even here,
> > though the super-micros built by folks like SGI and HP are chewing
> > away at the edge once held by mainframes.
> >
> > If you're stuck cramming your I/O through a SCSI bus, you'll never
> match
> > the performance of a system with multiple independent main memory
> busses
> > and multiple DMA channels that can move data at memory speed without
>
> > noticably slowing down the CPU.  Of course, even in this arena,
> > minicomputers of the 1970's began to nibble at the mainframe market
> > (the Modcomp IV computer, a 32-bit mini delivered in 1974, had 4
> memory
> > busses, 2 for I/O and 2 used by the CPU, one for instruction fetch
> and
> > one for operands).
> >
> > If you've got a legacy of ancient COBOL code, some of which was last
>
> > compiled 30 years ago and the source code itself is lost, you're
> likely
> > to want a mainframe!  IBM and UNISYS still make good money selling
> > mainframes to folks in that bind, where performance isn't the issue
> > but compatability is everything.
> >
> >                                         Doug Jones
> >                                         jo...@cs.uiowa.edu
>
> I agree, but I think another major advantage of mainframes is
> concurrency. We have 35,000 users with sub second response time (plus
> the 3 second satellite transmission time that we can not control). PC
> servers can't handle that concurrency.

[snip]

PC Servers... ? How can you compare a $20000 doller machine with a $XXXX
million dollar machine ?