From: Mathieu Bouchard <matju@...>
Date: 2005-05-03T22:26:35+09:00
Subject: Re: collections with values of fixed classes/lengths

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On Tue, 3 May 2005, Eric Mahurin wrote:

> I think you answered your own question - "sometimes memory
> usage considerations are more important than flexibility".  To
> get this memory efficiency you would only be able to store
> objects of one class because you would be storing only the data
> per element - no class information.  You wouldn't even be able
> to put nil objects in for a homogeneous array - you may have to
> pick some value to mean nil if you need that.

It's not just the memory usage. When data is more tightly packed in RAM,=20
one benefits from cache locality (that is, your data is more often in=20
high-speed RAM than in low-speed RAM), and furthermore, if the data is in=
=20
a CPU-native format, then you can do some pretty fast processing on it,=20
especially if using SIMD extensions such as MMX/SSE or Altivec.

This is important for me, as I *am* doing live realtime video processing.

(For that, I combine PureData, Ruby, C++, and then some asm).

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