- [Craig] In this video, we take a look at suitable storage devices and storage media for given situations and scenarios.
(uplifting piano jingle)
When deciding on which storage device to use for any given application,
you need to think about the requirements of the situation.
These include capacity: how much data needs to be stored?
Speed: how quickly does data need to be read and transferred?
Portability: if data needs to be transported, size, shape and weight are important factors.
Durability: how robust is the media? Will it be damaged by shocks and extreme conditions?
Reliability: does it need to be used over and over again without failing?
And of course, cost: how expensive is the media per byte of storage?
Our three main categories of storage are optical, magnetic and solid-state.
And here's a brief recap of the pros and cons of optical, magnetic and solid-state storage from our previous video.
So, let's consider each of the devices and how they compare.
Well, hard disks have a very high capacity; they access data reasonably quickly.
Although you can get portable hard disks, they can be bulky, and they really shouldn't be dropped.
Hard disks will eventually fail, but they tend to be long-lasting, and they're cheap as a byte-for-byte comparison with other devices.
Magnetic tapes have a high capacity, but they're very slow to access data.
They're highly portable and reasonably robust; they're fairly reliable but can be damaged if not handled carefully.
They're a cheap solution to high-volume backup.
Today, because hard disks are so cheap, they've largely been replaced by portable hard disks.
CD-R/RWs can only store 640MB of data; a DVD, around 4.7GB;
and a Blu-ray, around 25GB.
It's quite slow to access data from optical media, but for serial uses such as watching a film, this is not an issue.
They're very portable, being lightweight and very thin.
They're also pretty durable but susceptible to dirt and scratches, which can make them unreadable.
Data can be pressed onto them very quickly, making them ideal for large-scale data distribution.
Today, they're largely being superseded by online, cloud-based server farms of hard disks,
allowing users to access data from internet-enabled devices.
Whereas software was once distributed by CDs from the front of magazines,
now typically, magazines contain hyperlinks to online files.
This reduces the clutter of having lots of discs at home and is more convenient.
However, these connections are not always reliable, and hard disk space may be limited, particularly in games consoles.
Some people like to have physical copies, making DVDs and Blu-rays still a popular choice.
Solid-state storage is ideal for the wide range of embedded systems and small, portable tablet, camera and watch devices.
They have a reasonable capacity, which is suitable for most applications.
They're very rugged and suitable for situations where they are likely to get bumped, as they have no moving parts.
They're very reliable, although eventually they will fail because they have a limited number of read-write cycles.
Solid-state storage is still quite expensive byte-for-byte compared to other options,
but it's gaining popularity as the cost continues to reduce.
Today, solid-state drives are a desirable replacement for magnetic hard disks.
They are significantly faster, as they have no moving parts,
and any item of data can be accessed immediately without the need for a drive head.
As they're still expensive, it's not uncommon for desktop or laptop computers
to have both a hard disk for large storage of application data and a solid-state drive for holding the operating system.
Let's now take a look at a range of devices and storage scenarios.
So here, we have a helmet-mounted camera; in terms of capacity, we want to be able to store video footage.
We want to be able to quickly get the data on and off the media,
and it needs to be stored quickly, as we'll be capturing real-time video footage.
The device needs to be portable and it needs to be durable, as it will potentially receive lots of knocks and bumps.
It needs to be fairly reliable but we appreciate that, over time, we will need to replace it.
Given all the options, the best fit here would be a solid-state drive.
In the scenario of a desktop computer in an office, we have a need for high storage data capacity.
as we'll have lots of programs and user data.
We need to be able access these programs and the data reasonably quickly,
but portability is less of a concern, as is durability,
as the computer is going to be in one fixed place on the office desk and isn't going to be moved around very often.
It needs to be fairly reliable and the cost needs to be quite low byte-for-byte
because of the significant data storage requirements.
Therefore, the best fit here is magnetic media for the main hard disk,
but we could also consider installing a smaller solid-state drive,
just to make the computer a little faster when accessing the operating system.
In case of backing up 800GB of data in a travel agent's, we've got medium-to-high data storage requirements.
It doesn't need to be quick, but it would be ideal if it was portable so we could take the backup off-site.
It needs to be fairly durable and as a backup device, it needs to be very reliable.
We also want a medium-cost solution here.
There are a number of solutions.
Optical media probably wouldn't be sufficient because of the data capacity requirements.
Solid-state would be quite an expensive option given the amount of storage needed.
So, magnetic media would probably be the best; we could use tape, which would be small and also highly portable.
Transferring work between home and school is quite a common requirement,
and portable USB memory sticks are a simple and easy solution here.
So, we're talking about solid-state storage, as they need to have a reasonable amount of storage,
they need to be highly portable, durable and reliable.
On top of this, they need to be low-cost, as they're likely to be purchased by students.
A more modern solution - and becoming more common - would be the ability to access your files over the internet
using a range of cloud-based server options.
In terms of distributing a video game for consoles, we have a number of options here.
We could use optical media because the capacity is reasonably small,
though this is certainly changing with some modern, graphic-intensive games.
It doesn't need to be very fast because the consoles will typically install the software
off the optical device onto their own hard drive.
It does need to be portable, as you're likely to buy the game from a shop
or order it and have it delivered,
and it needs to be fairly durable and reliable but not overly,
as once you have it installed, there won't be much regular further use for the physical optical disc.
You'll also want to keep the cost down; all of these factors make optical media an excellent choice here.
On a DVD, you'll get 4.7GB of available storage, and this should be sufficient for your average compressed game.
Another option - and again, increasingly common - is to use cloud-based storage
and to have the game streamed and downloaded directly to your console's hard drive
after you've purchased them from an online store.
Long-term storage of training videos really depends on how big those videos are
and how they're going to be used and accessed.
It could be that if the training videos are quite small and you want to distribute them,
using optical media to distribute them is fine.
It could also be that, due to the size of the training videos,
that magnetic media or solid-state is your only option.
With this scenario, more information would be needed
so you fully understood exactly how the training videos were intended to be used.
Finally, let's consider listening to music on a portable music player.
Here, we've got sound files, which are not that large.
We do need the device to be portable, we need to be able to access the files quickly,
and we need to have the device being durable, reliable and, ideally, low-cost.
So here, the best option is probably solid-state storage.
Although it's more expensive byte-for-byte than magnetic,
it wouldn't be significantly expensive given the amount of storage we will want.
The requirements for portability, reliability and durability outweigh all the other considerations in this scenario.
(uplifting piano jingle)