CA Investigates: Hard disks with no moving parts

Of all of the technologies found in computers, its main storage device, ­ the hard disk, ­ has stayed pretty much the same for decades. Apart from one new type of connector, Sata, the only noticeable change has been capacity.

The first disks held around 5MB and now we see disks holding around 1TB ­ today – that’s 200,000 times the capacity.

Now there's a new kid in town, the solid state hard disk. A different kind of hard disk that uses computer memory chips rather than spinning platters.

If you think this sounds a lot like a USB memory key you’d be absolutely correct. Solid state disks share many of the advantages of USB memory keys including silent operation and a greater resilience to knocks and bumps; especially important when working on the move.

What’s new?
Solid state disks are made of flash memory, essentially memory chips that don’t lose their information when the power is switched off.

The idea of using flash memory as an alternative to hard disks is nothing new. These disks are the first aimed at consumers that not only look like traditional hard disks from the outside but use the same kind of connectors.

Because they are physically larger than USB memory keys, solid state disks can also fit more memory chips, so there is more space for documents and other files. One important attribute is that they do not require power to hold on to their information.

It used to be said that solid state memory cards were not suitable for ordinary use because they could only write files a certain number of times. This problem has largely been fixed but don’t defragment a solid state disk as this will reduce its life.

In fact, defragmentation is no longer required. The problem of a defragmented disk is the time it takes to gather bits of information scattered across it. A solid state hard disk takes no longer to access information whether it is in bits or one large chuck.

This has a constant benefit to performance, although solid state disks can be slightly slower when moving very big files.