Electronics
Portable storage
Introduction
The latest in portable storage lets you carry 500GB in your pocket.
There's no shortage of options for backing up or transporting data. We look at the different types of storage, and discuss the advantages of each.
Please note: this report does not contain test results or brand-specific recommendations.
DVDs and CDs
Digital Versatile Discs (DVDs)
DVDs let you store a lot more data than CDs. Most single-layer DVDs store 4.7GB of data and come in recordable (once only) or rewritable (many times) formats. Dual-layer DVDs will hold 8.5GB.
DVD multi-drives (which can read and write DVDs) are the most commonly available computer drive and most are compatible with the dual-layer format.
DVD formats
There are several competing formats for recording DVDs: DVD-R/RW, DVD+R/RW and DVD-RAM. Most computer drives will play all formats except DVD-RAM, a very rare and more business-oriented type.
DVD-R/RW and DVD+R/RW
When recordable DVDs first appeared, two rival groups came up with their own versions, hence the -/+ symbols. There’s no practical difference between them and new computers can handle both formats.
The R DVDs are only writeable once, but RW DVDs are re-writable. To back up files using R you'll need to use many discs. The RW format allows you to update the same disc over and over.
DVD-R DL / DVD+R DL (dual-layer)
Dual layer DVDs are able to store around twice the data of a single-layer DVD - usually 8.5GB. But they are only available in the writable R format, not the re-writable RW type. Dual layer DVD drives are newer so check that your computer can read dual-layer discs before purchasing. While they can store twice as much data as a single-layer DVD, they’re often more than double the price.
Which format to choose
The format you choose will be decided largely by the drive your computer has. Multi-format drives which read and write DVD-R/RW and DVD+R/RW discs are common.
If you plan to use a drive to record movies and show off your video-editing skills, DVD-R/RW and DVD+R/RW are the best options. They will play in stand-alone DVD players and other computer DVD drives.
In general, as long as you choose a drive that records a "write-once" format as well as rewritable discs, you shouldn't need to get too hung up on which + or - format to choose.
Price (approximate)
- DVD R single-layer 4.7GB: $0.90
- DVD RW single-layer 4.7GB: $1.50
- DVD R dual-layer 8.5GB: $3.50
Compact Discs (CDs)
CDs are an older optical disc and can store only a small amount of data compared with DVDs. CDs can store a maximum of 700MB compared with 4.7GB for a single-layer DVD.
Like DVDs, you can buy CDs in recordable or rewritable formats. Most CD R discs have a similar writing speed but RW discs can vary in speed from x4 to x24 – the higher the number, the faster it will write.
Most new computers have DVD multi-drives, but these are still able to read and write CDs.
Price (approximate)
- CD R 700MB: $0.50
- CD RW 700MB: $1.10
Blu-ray Discs (BD)
Blu-ray is a high definition video disc that is able to store 25GB on a single-layer, or 50GB on a dual-layer disc. DVDs have a maximum resolution of 720 x 576 pixels whereas Blu-ray discs can display 1920 x 1080 pixels. This makes Blu-ray discs ideal for those who want to store movies or their home videos in high definition.
Blu-ray discs come in a recordable R format or a rewritable RE format. Blu-ray drives are rare on new computers but are becoming more common.
Price (approximate)
- BD R 25GB: $14-18
- BD RE 25GB: $24
USB flash drives
USB flash drives (also called "USB keys" or "USB memory") plug into your computer's USB port and act like mini-hard drives.
They're small enough to fit on a key-ring and are ideal for portable data storage, especially for laptop users. They can store between 1GB and 128GB of data, and cost anything from under $20 for a small 1GB drive, to over $600 for a 128GB drive.
USB flash drives are generally very easy to use. If your computer is less than 5 years old, it should have multiple USB ports in which to plug the drive. If you're running a Windows Mac operating system you'll have no problems using it straight out of the box.
The portability of USB flash drives and their ability to be read by almost any computer makes them a good option for anyone who needs to transfer files between different locations, such as home and office. Several USB flash drives currently available are capable of holding over 100GB of data, around the same amount of data as a small laptop hard drive.
When choosing a USB flash drive, consider its features:
- Durability: It needs to be fairly robust and resistant to scratches and dust. Many have a key-ring or necklace for portability and this should be attached to the body of the drive, not the cap. Some models are waterproof and shock-resistant.
- Security: A write-protection switch allows you to prevent any files on the drive from accidentally being erased or rewritten. Some models have fingerprint readers that are highly accurate and can either deny access to the whole drive or just to selected files.
- Shape and size: There are hundreds of different models of USB drives. Most are of a sleek and practical design but there’s no shortage of humorous and attention-grabbing drives for sale (check out www.usbgeek.com for some examples.
External hard drives
Hard drive failure is the most common computer fault according to our computer reliability surveys, and if you haven’t backed up your data you could lose everything.
As CDs, DVDs and USB flash drives don't have the storage capacity to backup a full system, an external hard drive is ideal for the job. Some external hard drives can hold more than 2000GB (2TB) of data.
There are several types of external hard drive:
- Portable drives hold 250GB to 1TB and are usually small enough to be transported easily. Prices range from around $120 for a 250GB model up to $200 for a 500GB model or even $1000 for a 1TB model.
- Desktop drives hold 250GB to 2TB of data and are normally too large for easy transport (most are over 1kg). Lower capacity drives cost around $100-150 while drives of 2TB are typically over $300.
For more information, see our test report on external hard drives.
Backup software
Operating systems like Microsoft Windows Vista, Windows 7, and Mac OS X have backup features included. Many external hard drives come with backup software and some internet security suites include a backup component.
You can also download many free backup software programs from the internet.