By Prince McLean

Published: 11:00 AM EST (08:00 AM PST)

Time Capsule expands the wireless base station into a file and printer sharing solution and Time Machine target. This segment, the last of six exploring Time Capsule in depth, provides a review of its features and limitations as a wireless file sharing and backup appliance, along with comparisons to alternative products and previous AirPort models.

Previous articles from our in-depth Time Capsule review series:

Exploring Time Capsule: Time Machine over the Network vs USB
Exploring Time Capsule: 10/100/1000 Ethernet vs. 802.11g/n Wireless Networking
Exploring Time Capsule: WiFi 802.11n and the 5GHz band
Exploring Time Capsule: theoretical speed vs practical throughput
Exploring Time Capsule: how it fits into Apple's AirPort family
An in-depth review of Apple's 802.11n AirPort Extreme Base Station
Apple Time Capsule unboxing and preview
A Look Inside Apple's New Time Capsule
Answers to Time Capsule reader questions

The AirPort Family (Snap, Snap)

Based on our testing, Time Capsule is almost functionally identical to the AirPort Extreme in terms of disk sharing. The Time Capsule's built in SATA drive offers a slight edge in performance over an external USB disk, but users won't see a significant difference when working from wireless clients. The additional speed is really only visible to wired clients using Gigabit Ethernet.

Time Capsule offers Gigabit Ethernet as standard, while AirPort Extreme units sold prior to August 2007 only supplied 10/100 Fast Ethernet. Even so, the theoretical performance advantage of the faster wired networking isn't a clear reason to upgrade, as the file sharing features of the base stations are optimized for wireless and don't exploit the advantage of the greater throughput potential available in Gigabit Ethernet.

The actual difference in file serving from the base stations between the Fast and Gigabit Ethernet models is not very significant, although client systems connected via the faster Gigabit Ethernet switch integrated into the base station will be much faster when talking to each other, such as when sharing iTunes libraries or iPhoto albums.

To 5 GHz or Not To 5 GHz, That is the Question

All of the currently shipping AirPort base stations now support 802.11n, which includes support for the 5 GHz band. As noted in Exploring Time Capsule: WiFi 802.11n and the 5GHz band, there are both pros and cons to using this configuration. It can limit the reception area and have a harder time penetrating walls and floors, but it also supports the use of wide channels, which can dramatically boost the speed of wireless networking.

This boost can make the difference between a wireless setup that can't quite handle the demands of Time Machine backups while also streaming AirTunes and copying files, and one that takes it all in stride. Users should experiment to make sure they're getting the most out of their equipment given their own circumstances and needs.

Time Machine: Wired vs Wireless Networking vs Directly Connected Drives

Apple advertises Time Capsule as the ideal target for Time Machine backups, and for most users with casual needs, it serves as an ideal backup appliance: invisible, simple, and cost effective. While wireless networking is considerably slower than wired networks and lags far behind backing up to a directly connected USB drive, for most users, the length of time required to do regular incremental background backups won't be a big deal.



However, wireless restore operations, including the process of zooming into space to look up the missing files in Time Machine, are considerably slower over a wireless connection and incur delays that can make the process something between frustrating and irritating. Because restore operations are a foreground task requiring user interaction, and hopefully will occur less often than hourly backups, this problem can be worked around by connecting to the base station directly via Gigabit Ethernet before performing a restore.

In other words, regular background backups don't suffer from the slower nature of wireless networking nearly as much as the file intensive searching related to a Time Machine restore operation. Restoring files should be an occasional event that can handle the clumsier process of directly connecting to speed things up.

Time Capsule Wireless File Sharing vs a Standalone Gigabit NAS

Given that a PowerMac G5 can serve files over Gigabit Ethernet faster than a directly attached USB drive, it would be nice to see similar performance from Time Capsule. However, Time Capsule and the AirPort Extreme are designed to serve as wireless base stations, not as general purpose, high performance Networked Attached Storage appliances.

Being half as fast as a standalone computer over Gigabit Ethernet also allows Time Capsule to eat a fraction of the energy and dissipate far less heat than a G5 tower, and subsequently be much smaller. The performance edge of a standalone server also becomes invisible when most of the clients are using wireless networking to access it.

Once again, Apple has engineered a product that serves a specific purpose, rather than trying to do everything without doing anything very well. The result is that Time Capsule will satisfy the users it was designed for, and does not appeal to users with needs for something else. For those who do need a solution faster than the entry level base station's integrated file server can manage, there's the option of adding a standalone Gigabit NAS appliance to the network.

A terabyte standalone Gigabit Ethernet NAS device can range from about $300 to $1000, although most lower end systems use two 500 GB disks, making them considerably larger, power hungry, and likely nosier. On the other hand, they should also be significantly faster, and many models offer internal RAID features for additional protection against drive failure. Most devices are also configured over the web, making them more complex for non technical users to manage compared to the ultra simple and friendly AirPort Utility software used to set up Time Capsule and the AirPort Extreme.

On page 2 of 2: Time Capsule Wrap Up and Rating.