Pulling app code from cache vs. from disk

This question was posed to me, so I'm hoping somebody might have some clue: does anybody know the advantages/disadvantages of a Mac application pulling code from cache vs. pulling it from the hard drive every time the app is run? Any hints, ideas, etc? Tough question, I know, hope the points are sufficient to get you thinking. Thanks, Adam.
DyrewolfAsked:
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The_RavenConnect With a Mentor Commented:
That is a trick question...
For a Mac 68k, which does load code segments from the resource fork (Code 0 first and then as needed) the segment that is being will stay in memory until it's not in use and some other resource needs to take it's place.

For a PPC, the entire code set is loaded from the data fork and assembled as handles in high memory, it never leave memory or gets cached... (not to say that the PPC chips instruction cache isn't storing some instructions).

As far as the low level stuff and design... I would put constanly used routines in small code segments, this will help insure that they will get cached and stay there.
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naxCommented:
If I understand your question correctly, the main difference is speed.

Pulling codes from the cache (RAM) is a lot faster than getting it from the Hard disk everytime you use it since RAM is electronic and Hard disk is basically mechanical.  Using cache also helps to extend the life of your Hard disk since you only have to load the codes once, after that your Hard disk can rest and it's up to the cache to do the hard work.

The only disadvantage i can see is when you have very limited RAM. Using a large cache would lessen your total useable RAM which could lessen your ability to open other RAM-eating applications.

good luck!

nax
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DyrewolfAuthor Commented:
I was actually looking for a lower level answer, I think something to do with the nature of reloading applications' resource fork from cache. I got enough of an answer elsewhere to get by, but thanks anyway. Adam...
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DyrewolfAuthor Commented:
Sweet. That's basically what I was looking for...Adam
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