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From: slackey@bbn.com (Stan Lackey)
Newsgroups: comp.arch
Subject: Re: Memory utilization & inter-process contention
Message-ID: <45344@bbn.COM>
Date: 7 Sep 89 20:16:03 GMT
References: <1114@aber-cs.UUCP> <278@baird.cs.strath.ac.uk> <2089@uceng.UC.EDU>
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Reply-To: slackey@BBN.COM (Stan Lackey)
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In article <2089@uceng.UC.EDU> dmocsny@uceng.UC.EDU (daniel mocsny) writes:
>In article <278@baird.cs.strath.ac.uk>, jim@cs.strath.ac.uk (Jim Reid) writes:
>> A VM system general enough to perform well for most potential users and
>> their applications on most potential hardware platforms is asking a lot.
>
>And the cost of failing to give this to the users is a lot more.

This gets back to fundamental laws.  One of them is "special purpose
is always cheaper than general purpose [to do the same specific job]".
In other words, if you want the best paging performance on a VAX, you
get VMS.  Because UNIX is a general purpose tool, ie it was made to
run on anything, it can't be as good on a specific box as an OS that
was written and tuned to run on that specific box and nowhere else.

Giving up something is required for generality; no general purpose
machine is going to run FFT's as fast as an FFT box that costs the
same.

Now, lots of high speed box vendors have tuned their proprietary
versions of UNIX around their own architectures, usually taking
advantage of the specifics of their own boxes.  But the new version
is not general purpose.
-Stan