# Computing stuff tied to the physical world

## Storage – let’s do the math

In Musings on Jun 22, 2013 at 00:01

Doesn’t it ever end? Storage density, I mean:

That’s a 16 GB µSD card. There are also 64 GB cards, but they are a bit more expensive.

Ok, let’s see – that’s 0.7 x 11 x 15 mm = 115.5 mm3 in volume.

Now let’s take a 2.5″ hard disk. The dimensions are 9.5 x 70 x 100 mm = 66,500 mm3.

So an already-small 2.5″ disk drive (or cell phone, if you prefer) takes as much space as 575 µSD cards, if you don’t count the card slot or other mounting options.

Let’s go for the 64 GB cards, that’s a whopping 36.8 terabytes of solid-state data. At €50 each, that’d require a €28K investment for about €0.80 per gigabyte. I’ll pass for now :)

But how much is 36 TB? Well, you’d be able to store over 5 Kb of data for each living person on this planet, for example. And carry it in your pocket.

Hello sir. One millisec… let me check your name, travel history, family tree, and CV.

What a terrifying thought.

1. Yes it is scary. But that’s only 36.8 terabytes, a company as Microsoft uses far more than that for just one service. See the link below. Just think what the secret services can put up with their virtually unlimited resources.

http://blogs.windows.com/windows_live/b/windowslive/archive/2011/09/22/a-petabyte-per-week.aspx

2. Petabytes can be “cheap”, too: http://blog.backblaze.com/2009/09/01/petabytes-on-a-budget-how-to-build-cheap-cloud-storage/ And why take the db in your pocket when you can have it in a safe place and remotely query it? :)

3. This kind of pondering has made me wonder just how cheaply we could build a slow-access-speed but extremely extendable array of sdcard readers. Over time, there would be quite a few old cards around – amounting to a useful amount of storage (or just a convinient way to archive and read all the cards full of photos)