A client recently asked for advice about how to purchase an external hard drive. I’ve found that many people are confused about the various file formats and interfaces that are available.
The first rule is: don’t worry about the file format of the drive when you purchase it. It’s easy to reformat the drive before you start putting data on it.
The FAT32 file system can be read and written by both Mac and PC, which is why most drives come formatted that way.
However, for really large files (like video) the drive needs to be formatted as NTFS because FAT32 won’t work for files over 4 gigabytes. Both Macs and PCs can read NTFS, but the Mac operating system cannot natively WRITE to an NTFS formatted drive. The exception to this is in Snow Leopard, but even with the Mac Snow Leopard OS this functionality is disabled unless the user turns it on.
NTFS is more reliable that FAT32. But if you aren’t going to have very large files on the drive and you need for the drive to be writeable from a MAc, it might be simpler to leave it formatted as FAT32.
If you’re not going to be writing from a Mac, then the drive should definitely be reformatted as NTFS as this is a more reliable file system than FAT32 and you are less likely to have problems with files becoming corrupted.
Most drives come with a USB 2.0 interface which is standard on all but the most outdated PCs and Macs. Other options include Firewire (or 1394) and ethernet. For maximum compatibility you probably want a drive with a USB interface, since a lot of PCs don’t have Firewire. With an ethernet connection, you can connect your device directly to a router so all computers on your network can share it. You can easily find a drive that has some combination of these three interfaces.
Look for a drive with a long warranty. I prefer Seagate. Many of their drives come with a five-year warranty. Western Digital is another reliable brand that I have had good luck with.