hard drive - are 4 heads better than 2?

  • Thread starter Thread starter stockDrover
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stockDrover

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

The line offers 80.120.160.250.320.

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
two.

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
cylinders.

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


Nevermind just found out only one head at a time can read.

160 it is...

Bitchin deal on the 320's though 20.00 MIR makes them about 60.00.
 
stockDrover said:
I have to believe the drive gods are clever enough to map consecutive
clusters vertically through the platters thats why we call them
cylinders.

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.

Jon
 
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