Hard drives GB/£ ?

So I’m currently looking into buy a new hard drive for storage as I’m currently running a tad low on both of my 500GB Seagate Barracuda ST3500 drives.

Of course I’m looking at getting the most value for money, but my main priority is reliability. I’m going to be running the drive 5+ years, 24/7.

Some of the drives I’ve been looking at are:

Seagate ST1000DM003 Barracuda 1TB - http://www.amazon.co.uk/gp/product/B006BRBSE8


Western Digital WD1003FZEX Caviar Black 1TB - Amazon.co.uk

Of course I’ve had a look around, and found that WD have all these different colours for their drives, (maybe someone can tell me why Purple is more suited to CCTV rather than a Black, or Red or even Green?)

Speaking of which, my drives are more or less used for storing media content, wouldn’t a WD Purple be more suited to this task?

Like I said before, reliability is my main priority. It has to be to the tech world, like what Volvo is to the car industry. Built like a tank.

Oh and ideally I’d like to keep the price under £80.

Thanks dudes/dudettes! :wink:

WD green = For pc’s that require silent(ish) operation ---- Link

WD red = For NAS and servers that need to run 24/7 ----- Link

WD purple = WD Purple Surveillance Hard Drives are engineered for 24x7 reliable operation in HD security systems with up to five hard drives and up to 32 cameras.

WD Blue= WD Blue hard drives deliver solid performance and reliability while providing you with all the space you need to hold an enormous amount of photos, videos and files. These drives are designed for use as primary drives in desktops PCs, notebooks and external enclosures, and for certain industrial applications.

WD black=WD Black hard drives are designed for enthusiasts and creative professionals looking for leading-edge performance. These 3.5-inch desktop drives and 2.5-inch mobile drives are perfect for high-performance applications like photo and video editing, gaming and power PCs.

Or there’s a seagate barracuda here

That Barracuda drive is very tempting… Hm.

Given that you will be running it for 5+ years 24/7 I would go for the WD red.
It’s double the size you were looking for and still under £80.

My own personal experience keeps me away from Seagate … had too many of them fail whilst still quite young.

Just my experience, but what else can you go on eh :wink:

Still this seems to back me up:

coincidence ?

If reliability is really that important, shouldn’t we be talking RAID 1 or 5 here?

My theory of RAID 1 or 5 is that if one of the drives goes down, that’s half the data missing? How can that possibly be reliable?

Your “theory” is wrong then :wink:

RAID 1 is simple drive mirroring … so you have 2 copies the same drive … if a drive fails, replace it and the contents of the other mirror will be copied to the new drive (leaving you with 2 copies again).

RAID 5 requires (at least) 3 disks … where it stripes the data so benefits from the speed of parallel read/writes … but copies a third of the data from each drive to the other 2 (parity data) … so if a single drive fails ALL data is still present on the other 2, so replace the failed drive and it will be rebuilt from the parity data on the other two with ZERO data loss.

Best explained with diagrams … see here:


The explanation of “parity data” in the RAID 5 explanation above is overly simplified … really it’s a a calculation of the data on the other drives from which the original data can be rebuilt … but you get the meaning :wink:

Parity computations are used in RAID drive arrays for fault tolerance by calculating the data in two drives and storing the results on a third. The parity is computed by XOR'ing a bit from drive 1 with a bit from drive 2 and storing the result on drive 3
Thought I'd better add that before someone pulled me on it ;)

You’re thinking of RAID0 - great performance, but if you lose a drive, you lose the lot (no chance of recovery)
RAID1 is like an auto-backup, but it’s online (if you lose a drive, you don’t lose the system, it stays on and working with no “backup”)
RAID5 is the best of both worlds, but needs an extra drive.

RAID0 - 2 drives x 80Gb = 160Gb of fast performance, no data security
RAID1 - 2 drives x 80Gb = 80Gb of normal performance, good security
RAID5 - 3 drives x 80Gb = 160Gb of fast performance, good security

So, if you work it out (discounting RAID0 as it’s a bad idea), you get better Gb/£ with RAID5, but it has a higher initial cost as you need 3 drives.

RAID5 seems interesting. I already have two storage drives at the moment, so if I add another drive I could do RAID 5 right? Or do all the disks need to be the same storage capacity?

See the answer with the green tick here:

What are the various sizes? It’s probably that software raid via mdadm is the way forward, but the RAID array would be limited to the size of the smallest drive (the remaining space on the larger drive would still be usable, but wouldn’t be protected/enhanced by RAID - it would just be normal HDD space)