Drive (and memory) sizes, and the marketing scam

It has always annoyed me intently that the marketing departments of IT product manufacturers were ever allowed to barstardise the message to dumb it down for the average end-user.

What do I mean?  It is simple mathematics, and all boils down to the fact that computers are binary, and humans are decimal.

We are used to thinking of things in factors of 10, so how (marketing) applied it to IT is:

1kB is 1000 bytes

1MB is 1000kB

1GB is 1000MB

1TB is 1000GB

Nice and simple, so when you buy a 500GB drive, or a 1TB drive or whatever, you can easily figure out that 2×500GB drives is about the same as 1TB drive, or 5×100GB drives etc.  (This is not taking into account the amount that is actually lost during the formatting of the drive, where a 500GB drive can actually only hold about 430GB of information).  The problem is there is a fundamental error here, which is multiplying with each generation of device, and unit size.

So let’s look at what there really is as far as the computer is concerned, and see just how much difference it is making these days (and this started around the time of 100MB harddrives, so the error is getting pretty large!)

1 bit of information is a 1 or a 0

1byte is 8 bits (such as 0100 0001, which is the letter A)

Now, a little diversion – instead of writing lines and lines of code as 0100 1001 0001 1101 etc, it is much easier converting it to base 16, or hexadecimal.

So 1001 1101 is written as 9D

(Counting in Hexadecimal goes like: 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F, 10, 11 and so on)

FF is 1111 1111, or 255 in decimal. So one more is 100 in hex, 1 0000 0000 in binary, or 256 in decimal.

Now we start to see why RAM (for example) increases in multiples of 256, so historically, computers had 4K RAM, then 8, then 16, 32, 64, 128, 256, 512, 1024.  If you’ve been around computers for a while, these numbers start becoming strangely familiar.  It is all powers of 2: 2×10^2, 2X10^3 etc

Back to our topic.  The last number, 1024 is especially relevant to our conversation.

Because 1kB is actually 1024 bytes

1MB is 1024 kB

1GB is 1024MB

1TB is 1024GB

Doesn’t seem like a lot of difference from what the marketing guys did, but the error is compounding, and it is in favour of the marketers, not the consumer.  In other words, a 1TB drive actually can hold significantly less than an actual 1TB of data.  Yes I know they put the disclaimer in the small print (that 1TB represents 1000GB), but the error has been compounding since MB days so even 1000GB is a lot less than it actually is as far as the computer is concerned.

So let’s think of it a different way.

An A4 page full of writing can hold approximately 2750 A’s (I just worked it out in Word, so there are margins, font sizes etc all at play here, but let’s just take this as an average).

So, 1 page represents 2750 bytes

Putting this side by side with the marketing averaging:

Actual size	Actual A4 pages	Marketing A4 pages	Difference
1kB	0.37	0.28	0.09 Pages
1MB	381	363	18 Pages
1GB	390451	363636	26,815 Pages
1TB	399822410	363636364	36,186,046 Pages

Now I don’t know about you, but telling me that a drive is 1TB in size which can hold 36 million pages of A4 text less than a drive that actually measured a real 1TB is just wrong, no matter how much fine print there is.  Or in other words, it is 92GB smaller than it appears.  Which is about as much information that is on 2 complete floors of the average library.

When we get to the next generation, and we get our first Petabyte drive (1PB), this compounding error will cost us something like 90TB.  The printed collection of the US Library of Congress holds approximately 10TB.

Now you can see why I get annoyed when marketing is allowed to play with IT specifications!

Burnt….Again

I’m not sure how many times I’ve advised people about backing up – it’s like the property market “location location location”.  My catch-cry should be “backup backup backup”!

I have a reasonable backup regime in place, but obviously it is not perfect, and once again I’ve lost data, so let me just say this again for everyone’s sake, including my own:

Make sure that you ALWAYS have more than one copy of any file that is important to you.

Last night, I was cleaning up a number of files, and transferred about 12GB worth onto one of my main harddrives.  Unfortunately (stupidly), I moved the files rather than just copying them.  So that meant that I still only had a single copy of the file.

The drive that I moved the files to failed sometime between then and now, and has become unreadable, and so all the files that I moved have been lost.  The drive itself is rather large (1.5TB), and fortunately I have a backup of it, so the majority of the files are safe (but now at risk, seeing as they have become the only copy, and that is bad news.)So all that I have lost are the files that I moved (and 12GB is a pretty significant chunk even so).

So stop for a second and think – are there any files that are important to you that you only have a single copy of?  If the answer is “yes” then before doing anything else today, stop putting the problem into the “too hard” basket, and find out what you need to do to back them up, and do it!

Backup Drive

With the ever-increasing amount of data that people have (and rarely backup), the storage capacity of the backup solution is steadily increasing (or more precisely: exponentially where it comes to digital multimeda).

Once upon a time, a 1.2MB floppy disk was a significant storage capacity, then along came CDs, Zip drives, DVDs and I could go on and on.  There is a worrying trend that I am observing of people using USB keys, not only as a backup, but as the ONLY copy of their documents.  These devices are great for file transfer – they are compact, with pretty impressive capacity these days, and fast.  They also fail, and when they do so, there is very little that can be done to reclaim the data on them.

So use them by all means to transfer files from one place to another, but please, do not trust your only copy of a file to one!

Where it comes to backing up, there are a number of better options.  A high proportion of users would have less than 4GB of data in total, so the low cost solution of burning a DVD is certainly a good choice.  If you need larger capacities, (such as for large photo libraries, music collections etc), then an external harddrive becomes a cost competitive solution.

Something like this drive from Maxtor is a good choice:

Maxtor Onetouch 4 External HDD

It is small and light (around 170g, 125mm x 80mm x 15mm) and runs off the USB port of your computer.  It doesn’t need to be plugged into the wall, as it draws the power it needs from the USB port.

There are different models with different capacities, up to 320GB.  Inside is simple – it is a laptop harddrive, and that is why I regard them as being a good backup solution.  (Note I still say backup – I don’t trust any file to one location only – you should always have AT LEAST 2 copies of every file, (unless you don’t care if you loose it)).

This isn’t the only type of external harddrive that is available – I chose it to show here as it is a good example of this type of backup solution.