Time Capsule review
The 2009 version of Apple’s Time Capsule combines the mundane tasks of networking, file sharing, and backups into one device, and it includes some cool new features to boot. Time Capsule, basically an Airport Extreme base station with a 500GB or 1TB internal hard drive, is designed to be a wireless Time Machine target for one or more Macs as well as a NAS (network attached storage) device.
Time Capsule’s marquee feature is its ability to back up your Macs running Leopard using Time Machine over the network. Apple recommends that you connect your Mac directly to the Time Capsule for the first backup, which makes a copy of all files on your Mac; backing up that much data takes a long time over the network. I backed up my MacBook Pro’s 120GB of data to each Time Capsule connected via Gigabit Ethernet and it took a little over nine hours to complete the first backup.
After that initial backup, Time Machine will back up to the Time Capsule every hour (unless the Mac has been powered down or the previous backup took longer than an hour). These hourly backups are incremental - that is, they back up only files that have changed, or have been added since the last backup. Such backups take less time and are generally handily accomplished over a wireless connection.
One thing to remember is that Time Machine backs up at the file level. So, if you use a program that frequently makes changes to a large central file (like Entourage, which stores email in one large database file), Time Machine will back up that entire file, even if only one item in the file has changed. This can impact wireless backup performance, depending on how large those files are. You can also use one or more external USB drives attached to the Time Capsule’s USB port as a Time Machine target.