[comp.sys.apple] Optimizing

PGOETZ@LOYVAX.BITNET (06/27/88)

Lazlo: Optimizing does not mean writing 0s to unused portions of the disk.
That would do nothing for performance. Optimizing means relocating files on
the disk so they are contiguous, & hence can be loaded/saved faster.  It will
increase speed on a hard disk, but maybe not noticably except for BIG files.
Disclaimer:  I speak of disk optimizing as generally known.  What the author
of DDD or whatever was thinking of
when he wrote an "optimizer" is unknown to me. In other words, anything could
happen.

Phil Goetz
PGOETZ@LOYVAX.bitnet

tsouth@pro-pac.cts.COM (Todd South) (06/27/88)

In Article <8806270057.aa23609@SMOKE.BRL.ARPA> PGOETZ@LOYVAX.BITNET writes:

> Lazlo: Optimizing does not mean writing 0s to unused portions of the disk.
> That would do nothing for performance.

> Phil Goetz

Phil,

        I know one half of the team very well, and he has stated (I believe
it is also in the documentation) that this is exactly what the optimizer
does in DDD Pro.  In the Huffman algorythm, I think that Hex 00 is supposed
to be the single character that takes the fewest bits to express.  Therefore,
if one writes 00's to all unused area's on the disk the total compression of
the disk would be smaller.  Remember, we are talking about a *disk* packer,
not a file compressor.  It looks only at the raw data on a track.

Todd South

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