Gidday,
When I select a hard drive, I go by the number of cents per
megabyte. The motor and controller are for practical perposes at a
fixed cost for any HDD. The number of heads and number of platters is
essentially fixed but the writing technology increases the recording
density with time. To increase the number of platters means either their
thickness is reduced or more unlikely the height of the platterÂs
enviroment shell is made greater. So you see the physical limitations.
Tolerances become finer yet larger economies of scale in volume sales
compensate for increased costs of extra digital decoding technolgy that
comes with greater write density. The larger the capacity of the HDD
the more production quality is tested. The minium HDD you could buy has
the most inefficient platter utilisation which is reflected in the ratio
of cost to capacity. At the high end capacities, efficiency gains are
optimum but this area tests reliability. Apart from your own brand
loyalty, calculate cost per Megabyte for each capacity of HDDÂÅ. Choose
the lowest capacity which is simultaneously also at the lower(est) cost
per megabyte. Using the arguement of economies of scale this is where
the optimum volume sales*fair capacity product lies. Given that only a
smaller number of HDDÂs in capacity exist, this answer also tends to be
where the optimum product of reliabilty and capacity meet.
If you reuire greater capacity than the optimum provides, get more
than one hard drive as two sets of drive motors and control electronics
halves your data viability difficulties. You could duplicate your data
onto two HDDÂs so that failure in one warrants replcements without the
loss of important data
David
