December 05, 2012, 4:00 PM — You can never have too much digital storage, and the day will comesooner than you thinkwhen you wont be able to squeeze a single new file onto your computers hard drive. And if your primary computer is a laptop or an all-in-one desktop, you wont be able to solve the problem by opening the case and tossing in a supplemental drive.
One solution might be to rent storage space in the cloud, but buying a hard-drives worth of capacity is prohibitively expensive: 500GB of storage on Dropbox, for example, will set you back $499 per year. If you need just storage, as opposed to a service for file syncing or collaborating via the cloud, buying a portable hard drive is far more economical. For less than $200, you can get a 2TB drive that supplies four times the capacity of a Dropbox account. Pay for that storage capacity once, and youll own it foreverand you can take it with you wherever you go. Before you can choose the right drive, however, you have to identify your needs, wants, and budget.
Mac or PC: OS X and Windows use different file systems (HFS+ and NTFS, respectively), so most hard-drive manufacturers offer platform-specific models; the drives are preformatted accordingly, and the bundled software (if any) is compatible with the given platform. OS X can read files on an NTFS drive, but it cant write them. If you intend to use the same drive on both platforms, you can install software on your Mac that will enable it to do both: NTFS-3G is a free option. If you prefer commercial software, take a look at Paragon NTFS ($20) or Tuxera NTFS ($32).
Capacity: To determine how much storage you need, consider adopting this rule of thumb from drive manufacturer Western Digital: A 500GB hard drive can store approximately 100,000 digital photos taken with a 6-megapixel camera, or 125,000 songs encoded as 128-kbps MP3 files. Higher-resolution photos and music, of course, consume more storage.
Everything else being equal, a high-capacity drive will deliver a better price-to-performance ratio than a low-capacity model: For instance, a 500GB drive priced at $100 costs around 20 cents per gigabyte, while a 2TB drive priced at $180 costs just 9 cents per gigabyte. You wont regret buying more storage capacity than you currently need, because you will surely need more later.
Rotational speed: The rate at which a hard drive spins its platters has a direct effect on how fast it can read and write data. A drive spinning at 7200 rpm will deliver much better performance than a drive spinning at 5400 rpm. Some high-end desktop drives spin their platters at 10,000 rpm.