Ten years ago, users who ran out of storage capacity typically had only one choice: purchase an additional hard drive and add it to their PC, or exchange the existing drive with the larger replacement. Optical storage media such as recordable CDs or DVDs was either expensive or simply not fast enough to meet the demands of power users. The situation is different today, as USB 2.0 and Firewire are popular options that allow the connection of external hard drives to PCs, so users don’t even have to open their computers and spend time on installing additional drives. Enthusiasts opt for eSATA because this interface does not bottleneck fast storage solutions.

However, mainstream external storage solutions don’t provide true data safety, because a crashed hard drive still means the end of your digital data. Many storage vendors are aware of the deficiencies of basic, single-drive external storage products, which you can find in computer shops, electronic stores and even in convenience stores.

While the performance limitations of USB 2.0 or Firewire can be avoided by utilizing External SATA (eSATA), hard drives are still sensitive to damage, due to their hybrid nature: they consist of electronic components as well as rotating, mechanic platters. Although modern hard drives are more robust these days, despite ever increasing storage densities, the risk of losing data has to be taken seriously. Treating your hard drive nicely by providing adequate cooling and steady operating environments is important, but it still doesn’t protect you from hardware failures.

The best way to guarantee data safety goes is by storing data redundantly. If you store data twice, you won’t lose it should one storage component fail. An important part of a backup strategy is to store multiple copies of your data, ideally at different locations. But storing twice can also be implemented at a storage device level, meaning that data is mirrored on a second hard drive in real time. This approach was followed by Maxtor two years ago with its OneTouch III Turbo, which was a dual-drive external storage product, capable of running in RAID 0 mode for maximum performance and capacity, or RAID 1 for safety conscious users.

We received two high-end external storage products by LaCie and SimpleTech, which are based on the same principle of mirroring storage on a second hard drive. Although the LaCie drive came with two terabyte hard drives and SimpleTech’s sample was equipped with two 500 GB drives, both share the same principle, and are available at various capacity points.