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From: lsr@apple.UUCP (Larry Rosenstein)
Newsgroups: comp.sys.mac
Subject: Re: Multifinder & System Memory
Message-ID: <6576@apple.UUCP>
Date: Thu, 29-Oct-87 19:33:41 EST
Article-I.D.: apple.6576
Posted: Thu Oct 29 19:33:41 1987
Date-Received: Wed, 4-Nov-87 03:22:06 EST
References: <17927@yale-celray.yale.UUCP> <2113@sputnik.COM>
Reply-To: lsr@apple.UUCP (Larry Rosenstein)
Distribution: na
Organization: Advanced Technology Group, Apple Computer
Lines: 38

In article <2113@sputnik.COM> moriarty@tc.fluke.COM (Jeff Meyer) writes:
>
>It [Multifinder] always shows the System file as taking up some memory.
>Anyone know if the amount of memory the System file takes up is any greater
>if you have more DAs and Fonts stored in the System file, i.e. size of
>System File is proportional to the amount of RAM reserved for it in
>Multifinder?  If it does take up more room, than Suitcase can save you
>substantial amounts of memory.

I think the number shown under 'System' indicates the amount of memory that
is allocated to something other than applications.  The System heap, RAM
cache, Macsbug, etc. all contribute towards this figure.  For the most part,
everything except the System heap size is fixed.  Under Multifinder, the
System heap can grow and shrink (provided nothing is in the way).

Resource maps are allocated in the System heap, so as the map for the System
file grows, the amount of memory required in the System heap grows.  The
incremental overhead (in the map) for adding a resource is 12 bytes plus the
size of the resource name (if any).  Therefore, adding fonts and DAs will
increase the memory required by the System.  

I don't know how Suitcase works.  If it keeps all the DA & font resource
files open, then it will increase the memory usage, since there will be
several resource maps in memory at once.  If it only opens one file at a
time (as it needs it), then the memory requirements will be less.




-- 
Larry Rosenstein

Object Specialist
Apple Computer

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