hard drive - are 4 heads better than 2?

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I am buying a new drive from the Hitachi 7K320 line...very nice

The line offers

All drives through 160gb are one platter. The rest are two platters.

I was settled on the the 160 as the highest density on one platter.
Since it is  for my laptop it goes without saying that heat is the
enemy, so I reasoned that 1 platter is better than 2. Less mass = less
inertia, less inertia=less power. less power=less heat. I know we're
talking little nits here...the big nits have been taken care of. chech
the specs

http://www.hitachigst.com/portal/site/en/products/travelstar /

The 80 is a 160 with a broken head
the 250 is a stack of 120's
The 320 is obviously a stack of 160s.There are 4 heads instead of

4 sectors can be read/written simultaneously.

I have to believe the drive gods are clever enough to map consecutive
clusters vertically through the platters thats why we call them

Though theoretical, the 4-head could be possibly twice as fast as the
2-head in reading or writing in some cases.

If this was the case then I would be willing to put up with a little
less battery life. If its not  the case, then drive geometry and
mapping has taken some wierd turn where its efficient to have 3 out of
4 heads idle on every stroke.

The specs at Hitachi are for the whole  family,not broken down by
drive. So I'm having a doubt:

All else being equal:

Will the 320/2-platter/4-head perform better than a 160/1-platter/2-
head or not?

Thanks for  playing, send fish

Re: hard drive - are 4 heads better than 2?

On Sat, 14 Feb 2009 14:43:46 -0800 (PST), stockDrover

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Buy based on the capacity you need, remembering that the
outer tracks of the drive will be significantly faster than
the inner so ideally you want a drive quite a bit larger
than the data it will hold.

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Doubtful, the probably only use one side of one platter, not
including the other head at all.

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Maybe, or it seems as likely they use two platters but only
one side of one of them.

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Based on what?  This is generally not borne out in

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In actuality this isn't true.

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You won't significantly effect battery life by picking only
one platter instead of two, though it might make the drive a
little longer lasting through lower motor heat and wear, and
fewer mechanical (heads) to crash someday.

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All else being equal, performance with the same platter
density and RPM will be similar with all models in the same
family, generation.  Pick the drive with a capacity more
than double that of the data you'll store on it.  You might
also consider partitioning off only as much of the space as
you might ever need for the OS, at the beginning of the

Re: hard drive - are 4 heads better than 2?

"stockDrover" wrote:
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The reason they are called cylinders is because that is their geometrical
shape, a cylinder.  Been called a cylinder even before multi-platter storage
systems; even the lowly floppy disk had cylinders.


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