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Re: Mac Mathematica & memory requirement

• To: mathgroup at christensen.Cybernetics.NET
• Subject: [mg233] Re: [mg197] Mac Mathematica & memory requirement
• From: Xah Y Lee <xyl10060 at fhda.edu>
• Date: Fri, 25 Nov 1994 21:42:55 -0800 (PST)

On Fri, 18 Nov 1994, David Crawford wrote:

> I want to buy more memory for my new powerbook (520c, 
> 68040, no FPU).
> 
> How much do I need to allocate to Mathematica
> non-enhanced ?

How much memory you need depends on what you do with mma. For general 
purpose, I'd say 10 M minimum. I use mma to create animations a lot, so I 
alawy run it with 20M. I have 9M physical RAM. I am using system 7.1 with 
virtual memory. Occasionally I can hear my harddisk spinning swapping 
memories, but mostly there's no speed problem with virtual memory in mma 
on my setup.

> If I upgrade this powerbook with a plug-in PowerPC chip, 
> and upgrade to the PowerMac native version of Mathematica 
> will I require more memory than when using the native 680x0
> version ?  How much more?

There shouldn't be any difference.

> I am aware that the minimum required memory allocation
> for Mathematica is only a _minimal_ allocation to make
> Mathematica barely run, and that giving mma more memory
> can greatly improve its performance.   Is there
> any limit to benefits from more memory ?   Is there a 
> point where additional memory will yield no additional
> performance ?

Assigning extra memory does not improve mma's performance. It only extend 
memory intensive capabilities such as graphics in one session. BTW, as 
you know, you can always quit and relaunch when you run out of memory. 
BTW, quit and relaunch is the easist way to purge whatever mma kept in 
your session.

> So how much memory to allocate to Mathematica ?
> 
> 680x0 non enhanced:    ___MB
> PowerMac Native:       ___MB

If you really enjoy mma and constantly have HUGE projects with lots of data, 
buy as much as you can afford. Otherwise, 9M physical RAM along with 
virtual memory works for me fine.

 Xah
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