Quote:
Originally Posted by nano1000
So a yottabyte of storage would be as big as multiple states and would cost 100 trillion dollars, almost twice the gross domestic product of the world.

I assume you refer to this:
it's not really true.
a 4TB external drive is available in a 3.5" form factor,
that's roughly 1" tall 3.5" wide and 5" long. cost £151 from Dabs
so 1TB = £37.50 (or there about)
so 1 Petabyte = £37,000 (thirty seven thousand)
1 extabyte = 37,000,000 (thirty seven million)
1 zetta byte = £37,000,000,000 (thirty seven billion)
1 yotta byte = 37,000,000,000,000 (thirty seven trillion pounds).
a fair amount, just over twice the national debt of the states in fact, but nowhere near twice the worlds GDP.
List of countries by GDP (nominal)  Wikipedia, the free encyclopedia
which the UN estimates to be around 70 trillion dollars. since I started my working in British pounds that's 45 trillion pounds.
so 1 yottabyte of storage (in currently available external HDDs) costs about 3/4 of total world GDP.
now lets look at the size.
(1YB = 1000ZB = 1,000,000EB = 1,000,000,000PB = 1,000,000,000,000TB)
so in 4TB disks we need
1,000,000,000,000 / 4 = 250,000,000,000 (two hundred and fifty billion disks)
at ~1 x 4 x 6" (which allows for some airflow) per disk.
well 10" x 40" x 60" would be 1000 disks.
the average computer rack is 42U high, 19" wide, and 36" deep (I'm guessing on the depth) 1u = 1.25" = 52.5" (you can get 46u racks, so I'll assume you can stack ten disks long side up going up in a rack)
so we can roughly squeeze 2000 disks into a single rack.
(standing on end that's about 20 across the rack, ten disks going up the rack, and ten disks deep. (20 x 10 x 10 = 2000)
250,000,000,000 / 2000 = 125,000,000
So one hundred and twenty five million racks of disks.
with each rack being 19" wide and 36" deep
to allow for the actual rack frame work, cabling and airflow as well as 2ft corridors between racks for people to walk. we'll call each rack standard height.
5ft deep and 2ft wide. (10 square feet per rack installation)
so with each rack needing 10 square feet of space. and with a storage density of (8EB per rack) you end up needing 10,125,000 square feet of space for 1 YB.
there are 5280 feet in 1 mile, so a square 1 mile long and 1 mile wide has 27,878,400 square feet.
just over twice what we need.
so while it's a cool rumour that 1 YB of data costs twice all the money in the world and fills half of America.
in fact it just costs a lot, and would only fill a reasonable sized village inside a small town if made of external hard drives.
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