The anatomy of size

Everything is shrinking. More and more our computers are resembling tablets and the smartphone has morphed away from Bell’s dream “Cos hey, who calls any more?!”

So far my columns have focused on the online or mobile/smart devices. For a change I am going back to the hardware basics This month’s column is about the size and memory capacity of your computer. It’s a mash up of:

  • what those computer spec and figures actually mean,
  • what all these figures mean in todays technology, and
  • what the basic anatomy of your computers memory.is

If you are an expert on computer hardware or were forced to become an expert recently when you had to buy a new computer sorry this months column may not be for you. But for everyone else who just smiles and nods when someone says cache …it’s time to go down the rabbit hole so please read on.

To start with a bit about bytes.Most of you will know that a GB is bigger than a MB and a MB is bigger than a KB but here’s what they actually mean.

There are 8 bits in a byte (B).
The smallest unit of memory, the Bit. In the computer world the Bit is an atom.The smallest unit of measurement its either a ‘0’ or a ‘1’What does a byte make?

There are 1, 024B in a kilobyte (KB)
These days a KB doesn’t make much. A five page paper (no pictures) is approximately 100KB.
If you cast back to 1981 the KB was a bigger deal. In 1981 the first remotely affordable home computer had a capacity of 16 kilobytes. If you splurged you could bump it up to 256 KB.

There are 1,048,576 bytes or 1,024 KB in a Megabyte (MB)
Which is just under 1000 pages of plain text. (4)

There are 1,048,576 KB or 1,024 MB in a gigabyte (GB)
Now: 2GB is the approximate size of a high quality legally downloaded 90 minute movie or approximately 341 digital pictures. (4)

And finally, there are 1,048,576 Megabytes or 1,024 Gigabytes in a terabyte (TB)
A terabyte is 233 DVD’s, bonus features and all, or Peter Jackson’s entire directing career line up.

There’s also the crazy sizes, a petabyte, exabyte, zettabyte and yottabyte.

and now for a curve ball

Whats the size of the internet?
With approximately 3 billion users (2) its hard to put a number on it. Back in 2010, Google said it had indexed 200TB of data which was estimated to be about 0.004% of the internet(3). It’s hard to put a number on it but is big. Really, really big.

The Opte Project created visualisations of the internet at 2003 and 2010. Personally, thinking about all these figures and trying to visualise the internet results in that sinking feeling I get when thinking about how big the universe is.


The internet in 2003
http://www.opte.org/the-internet/
© 2014 by LyonLabs, LLC and Barrett Lyon

The Horsehead nebula
http://hubblesite.org/gallery/album/heritage/pr2013012a/
Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

One thing about computers is this size doesn’t mean anything if there is nowhere to store it. There are two key types of computer storage: volatile memory and non-volatile memory.

Volatile memory is unstable and impermanent. It is the memory that disappears when your computer shuts down. On your computer the volatile memory is the Random Access Memory (RAM) and the cache memory.

Controlled by the computers Central Processing Unit, or CPU, the RAM is the computers primary memory sequence. A lot of RAM’s purpose and advantage is in the name. The data stored in the RAM can be accessed at random and is used by the CPU in the computers general operations. Before the CPU looks to the RAM however, it first checks the cache.

Closest to the CPU, the cache memory is the CPU’s first point of call when its looking to access data. Smaller and faster than the RAM, the “basic purpose of cache memory is to store program instructions that are frequently re-referenced by software during operation.”(1) Rather than retrieving the data directly from the RAM every time the cache stores frequently required data/instructions. What does this do? It makes your computer faster.

Unlike the volatile memory, you as the user have more of a say regarding the activities and contents of your computers non-volatile memory. The non-volatile memory is the stuff that stays where you put it unless you delete it or tragedy strikes and it gets corrupted. The primary piece of non-volatile memory is your computer hard drive. The hard drive stores everything, programs, files, everything that makes your computer yours when you turn it on.

Other examples of non-volatile memory are external hard drives, memory sticks (aka USB sticks or thumb drives), CD’s, DVD’s and the venerable, ye olde floppy disk.

References & Further reading
(1) Tech Target http://searchstorage.techtarget.com/definition/cache-memory
The difference between RAM and Cache – http://www.differencebetween.com/difference-between-ram-and-vs-cache-memory/
(2) http://www.internetworldstats.com/stats.htm
(3) http://www.websitemagazine.com/images/blog/adayoftheinternet_info.png
(4) http://www.computerhope.com/issues/chspace.htm

Further reading

https://web.stanford.edu/class/cs101/index.html

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