Monday, April 9, 2012

One Hard Disk Drive

I now have four hard disk drives in my desktop computer. But this arrangement, as common as it was a few years ago, doesn’t make much sense now.

The new drive, which I installed yesterday and finished configuring overnight and this morning, has a capacity of 2 terabytes (TB). It’s clear enough that 2 TB is the go-to capacity for hard disks right now. A 1 TB drive has half the storage capacity but costs just 20 percent less. A 3 TB drive, with 50 percent more storage, costs more than twice as much.

With a primary hard disk drive that has a capacity of 2 TB, it is hard to say what the other three drives are for. Combined, they offer less than 1 TB of storage. Yet each drive uses 5 watts of peak power regardless of its capacity. I will surely want to unplug the three older drives to save electricity. As an extra benefit, pulling those drives out will make the computer less than half as loud.

It is hard to explain how much storage 2 TB is. One way I look at storage capacity it is to compare it to a $15 million data warehousing project I worked on in the mid 1990s. The data warehouse had so much data when it started out that it was stored in two rooms of computers, spread across two states. And that was for one terabyte. I now have two on a single disk.

Another way of looking at it is the question of how many files I can store. It would be impossible to fill up even 1 TB with a lifetime of personal files. Media files are another story. One of the files on my computer is the feature film Slacker Uprising. In standard definition video, compressed for Internet download, it takes up almost 1 gigabyte (GB) of storage. I am not an avid movie fan, but if I were, I could save a year’s worth of feature films on my computer for later viewing, and that would be only 365 GB, or one sixth of the capacity of the hard disk.

I never quite filled the 500 GB of my previous primary hard disk. Realistically, I won’t be filling up a 2 TB hard disk with files until I am editing a feature-length film of my own, a project that, alas, is not in my immediate future.

There is something to be said for having a second hard disk drive as a backup device. In less demanding applications, though, to save electricity, a backup drive should be an external drive. Then, it only has to be on about one hour per week. Inside the computer, it is on whenever the computer is on, burning through potentially $5 of electricity per year. In the strictest security setups, the use of an internal mirror drive may make sense as a way to guard against data loss.

Aside from that scenario, and that of demanding computer tasks like video editing, the era of desktop computers with multiple internal hard disk drives is over. When it’s just a question of storage, now that 2 TB is the standard capacity for a hard disk, one hard disk drive will almost always be enough.