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From: rpeglar@csinc.UUCP (Rob Peglar)
Newsgroups: comp.arch
Subject: Re: 64 bits
Summary: The more things change..
Message-ID: <224@csinc.UUCP>
Date: 17 Aug 90 13:36:42 GMT
References: <5539@darkstar.ucsc.edu> <13285@yunexus.YorkU.CA> <30728@super.ORG> <9660@ganymede.inmos.co.uk>
Organization: Control Systems, Inc., St. Paul MN
Lines: 71

In article <9660@ganymede.inmos.co.uk>, stevem@f40.inmos.co.uk (Steve Maudsley) writes:
> In <40713@mips.mips.COM> John Mashey discusses some of the issues of space
> relating to DRAM. 
> 
> To support his premise that big word-size machines will be in common
> use, I would like to pass on a few observations about the 
> semiconductor industry
> 
> 	1. It takes about 10 years for a new manufacturing technique to 
> 	  become used in production from the time that the proof-of-concept
> 	  has occured in the labs. Hence, we can identify now the techniques
> 	  that will be in use in 10 years time.
> 
> 	2. With a judicious use of imagination, there are now a sufficient set
> 	  of techniques availible to produce 1GBit monolithic DRAMs in 2000.
>           These chips will be only about twice as large as current generation
> 	  DRAMs and that only to get the signal wires out.
> 
> 	3. In volume production, all DRAM technologies cost the same amount
> 	  per chip (in dollars), regardless of the generation.

No problems with 1. and 2. above.  3. assumes "cost"==marginal cost.  It is
valid to note that as time goes by (and DRAM becomes denser), the cost of
starting up - capital expense - goes up in both real(constant) and today's
dollars.  This is not trivial; in fact, it is the major reason why US
"players" in the semiconductor industry are reluctant to begin projects.
Not so for other nations where the cost of capital is (relative to US)
quite low.  US Memories, where are you?  BTW, no value judgements here, don't
read any in, please.

> 
> This nebulous set of observations implies that a 16Gbyte machine will have the
> same memory cost as a current generation 64Mbyte machine, which we now commonly
> use as NFS or X servers and consider an acceptable cost. NOTE: this is real
> memory, not virtual memory which is typically 10 times bigger because with 
> current technologies it is 10 times cheaper. Therefore, machines with 160Gbyte
> of address space will be affordable.
> 
> You will need more than 32bits address space for these machines.
> 
> I haven't addressed the issue of what you do with it, but certainly we will be
> using machines this size for simulating the logic circuits that we will 

I know quite a few people who would be delighted to have a microprocessor that
had a 64-bit address (text) space.  They would be even more delighted to have a
48-bit or 64-bit data space.  As for "ya gotta have the disk to back this", 
sure, but the cost of external storage (non-volatile) - french for "disk" -
is falling fast ($/GB).  Magnetic media are around $2x00/GB, shop around for
the best x.  Optical media is following the trend.  Even down and dirty
DRAM would be (probably) $70,000-80,000/GB;  certainly feasible for some
people.

The argument that 16GB of disk is unimaginable is rapidly vaporizing into
the other "gee, it's only a PC" myths of days past.  The day of 64-bit
microprocessors backed by hundreds of MB of fast DRAM backed by tens of
GB of disk *on the desktop* is n years away.  I am excited because n is
small.


Rob






-- 
Rob Peglar	Comtrol Corp.	2675 Patton Rd., St. Paul MN 55113
		A Control Systems Company	(800) 926-6876

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