Hard Drives

Hard drives remain the leader for storage and speed versus size. While flash-based USB drives remain the tiniest drives out there, physical size isn’t everything. Hard drive makers continue to put a lot of R&D into raising performance and increasing storage density: Putting half a terabyte in a 2.5-inch laptop drive was unthinkable not that long ago, and we reviewed a bunch of 500GB as well as some 320GB drives, all based on spinning platters—no SSDs here—all of which are thoroughly portable and run solely on the power delivered over USB or FireWire.

How We Tested

Time is the scarcest resource we have, so it made sense for us to focus on the speed of the drives in this roundup. To test the drives’ performance, we created a fresh install of Leopard with all the latest updates and turned this volume into a disk image that could be easily restored with Apple Software Restore (ASR), which is built into OS X. We then built a custom tool that performed this task three times on each drive, which allowed us to average the test results. This gave us a more representative sense of each drive’s overall performance. ASR can run in two modes: block copy, which is the fast option, and file copy, the slow one. We set things up to use block copy, since it pushes data at a drive as fast as possible.

Our test system was an 8-core Mac Pro, so plenty of processor performance was available. Each run of the test included the restore, 
which writes the data to the drive being tested, as well as a verify, 
which reads it all back to make sure that data integrity wasn’t compromised in the process.

In the real world, users perform far more reads than writes on a typical hard drive, so using a 1:1 ratio of read:write in a benchmark 
isn’t realistic. However, this ratio isn’t that far off for a drive used 
for Time Machine backups or for sneakernet. For this reason, we 
feel this benchmark methodology fit this particular collection of 
drives well.

LaCie

500GB Rugged Hard Disk USB, FW800, FW400
LaCie www.lacie.com 
PRICE: $279.99 
REQUIREMENTS: USB, FireWire 400 and/or FireWire 800 ports 
Physically robust. Difficult to lose due to bright-orange color.

Average performance. Comparatively large size.


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500GB Rugged Hard Disk USB
LaCie www.lacie.com 
PRICE: $219.99 
REQUIREMENTS: USB port 
Physically robust. Difficult to lose due to bright-orange color.

Average performance. Chunky form factor.

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LaCie

LaCie 120GB Little Disk
LaCie www.lacie.com 
PRICE: $199.99
REQUIREMENTS: USB port
Small. Capacious for its physical size.

Slow for a hard drive

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Other World Computing

320GB Mercury On-The-Go Pro Triple 7,200 RPM
Other World Computing www.macsales.com 
PRICE: $179.99
REQUIREMENTS: USB, FireWire 400, and/or FireWire 800 ports
Cool case. Fastest 7,200rpm drive we tested.

Metal heat sink on drive’s bottom can scratch surfaces.

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320GB Mercury On-The-Go Pro Triple 5,400 RPM
Other World Computing www.macsales.com
PRICE: $149.99 
REQUIREMENTS: USB, FireWire 400, and/or FireWire 800 ports
Cool case. Solid performer.

Metal heat sink on drive’s bottom can scratch surfaces.


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Seagate

500GB FreeAgent Go For Mac
Seagate www.seagate.com
PRICE: $239.99
REQUIREMENTS: USB, FireWire 400 and/or FireWire 800 ports
Fast. Large capacity. Well designed.

Thicker case than the USB-only version due to the height of the FireWire 800 port.


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500GB FreeAgent Go
Seagate www.seagate.com
PRICE: $199.99
REQUIREMENTS: USB ports
Amazingly slim. Great design.

USB only.


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320GB FreeAgent Go For Mac
Seagate www.seagate.com
PRICE: $189.99
REQUIREMENTS: USB, FireWire 400 and/or FireWire 800 ports
Fast. Well designed. 

Thicker case than the USB-only version due to the height of the FireWire 800 port.


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Toshiba

Toshiba 400GB USB 2.0 Portable External Hard Drive
Toshiba www.toshiba.com
PRICE: $179.99
REQUIREMENTS: USB port
Toshiba is a trusted name in hard drives.
Poor performance.

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Western Digital

500GB My Passport Essential
Western Digital www.wdc.com
PRICE: $199.99
REQUIREMENTS: USB port
Fastest USB performer.

USB only.


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500GB My Passport Elite
Western Digital www.wdc.com
PRICE: $219.99
REQUIREMENTS: USB port
Fastest USB performer. Sliding USB cover.

USB only.


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500GB My Passport Studio
Western Digital www.wdc.com
PRICE: $249.99
REQUIREMENTS: USB, FireWire 400, and/or FireWire 800 ports
Fastest USB performer.

Poor FireWire performer. Thick case.


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Drive Performance at a Glance
Speed isn’t everything, of course, but it’s a huge factor in any external storage buying decision.

Click image to enbiggen

Reads vs. Write
When looking at a drive’s performance, you want to pay closer attention to its read speeds, since most users perform more reads than writes to a typical drive. Bars show read and write times, in seconds, 
for the set of drive tasks described 
in “How We Tested”. NOTE: SHORTER BARS ARE BETTER/FASTER.

Click image to enbiggen

USB vs. FireWire—Speed and Power

Look at any spec sheet for a USB device and it will usually proclaim that it supports high-speed USB 2.0 at up to 480 megabits per second. Contrast that with FireWire, which comes in 400- and 800-megabits-per-second flavors, and you might assume that USB performs somewhat better than the former and not as well as the latter. Well, you’d be wrong, and we’ve got the test data to back it up.

FireWire was designed from the outset to provide high-performance data transfer between devices, but at the cost of having to put more intelligence inside each device, which raised per-device cost. USB, on the other hand, was designed so that the external device could be built as inexpensively as possible, leaving all the smarts inside the computer. This decision, which puts much of the transfer burden on the computer rather than the device, also results in a measurable loss of performance. Most applications that use USB today—keyboards, mice, or audio devices—don’t bump up against the USB performance ceiling. But USB mass-storage devices, such as external hard drives, definitely do. As our test results show, USB does the job, but it’s much slower than even FireWire 400. This is particularly noticeable with the drives we tested that have both FireWire and USB: USB lost the race every time.

It’s Got the Power.

Back in the early days of FireWire, it had one irrefutable benefit over USB: delivering enough power to keep a hard disk going. FireWire can deliver up to 45 watts of power, which is plenty to start a drive’s platters and keep them spinning. The USB spec, in contrast, provides 500mW for so-called low-power devices and 2.5W for so-called high-power devices. While 2.5W previously couldn’t power very much, today’s laptop-grade drives are so thrifty with their electrons that a USB port’s worth of electricity is enough to run a hard drive. Some USB ports have had difficulty delivering enough juice and, as a result, some drive manufacturers have taken to providing Y-cables with their drives: One USB connector for both power and data, and a second to supply an additional port of power. The downside is that this uses up two USB ports on your computer—and many laptops these days only have two to start with.

USB remains more ubiquitous than FireWire, and even Apple has decided that unless you’re a MacBook Pro or Mac Pro owner, you don’t need FireWire anymore, which is a shame, since the performance difference is pretty significant.

USB 3.0 SuperSpeed and Future FireWire. 

Just as this article was going to press, the USB Implementers Forum—the trade group behind USB standards (www.usb.org)—announced USB 3.0, aka USB SuperSpeed. USB 3.0 is supposed to provide throughput of up to 4.8 gigabits per second, a hefty 10x speed bump over the USB 2.0 spec. Not only that, but USB 3.0 is also slated to deliver 10.8W of power, another substantial increase. USB 1.0 and 2.0 devices will be backward-compatible with USB 3.0 ports, which is good news for anyone who likes to keep their older Macs and Mac peripherals around as long as possible.

In contrast, FireWire 1600 and 3200, which offer throughputs of 1.6 and 3.2 gigabits per second, respectively, were both approved as IEEE standards in July 2008. Both of these higher speeds use the same physical connector as FireWire 800, and are also backward-compatible.

It seems likely that FireWire 400 has reached the end of its life, and while FireWire 800 looks to be significantly inferior to USB 3.0 on paper, our experiences with USB 2.0 compared to FireWire 400 lead us to reserve judgment on FireWire 1600’s and 3200’s viability until we can compare them to the first real USB 3.0 devices, which are expected to start shipping in late 2009 or early 2010.