WiebeTech ComboDockReview date: 15 April 2004.
Last modified 03-Dec-2011.
External boxes for hard drives, as I mentioned just yesterday, are not very exciting products.
Some do the job better than others, but they're all much the same thing at heart.
WiebeTech came up with a new idea, though. Plug-in modules that attach to the back of a bare hard drive and turn it into a FireWire or USB device - no screwdriver required.
The $US169.95 ComboDock turns an ATA hard drive into a USB 2.0 and FireWire device.
(You can apparently use it with optical drives as well, if you buy an extra $US19.95 adapter, and possibly also update the firmware.)
WiebeTech hail from the mystic land of Macintoshia, so their product line has a slight slant towards FireWire, the One True Interface of the Technologically Pure, and away from smelly heathen USB. The ComboDock swings both ways, though.
People who haven't been keeping up with tech trends may wonder what a couple of the connectors on the back of the ComboDock are.
Power switch, DC input, mini-USB connector; check. Those other two framed plugs, though, are IEEE-1394b sockets - FireWire 800 (Apple PDF propaganda here).
The FireWire flavours are named for their theoretical bandwidth in megabits per second. FireWire makes better practical use of its bandwidth than USB, so FireWire 400 is likely to be a bit faster than "480 megabit per second" USB 2.0. FireWire 800 is twice as fast again - not a big deal for single drive applications, but helpful if you're connecting multiple drives to one controller and want to use them all at once.
That's what the two ComboDock 1394b connectors are for - they let you daisy-chain another FireWire device onto the ComboDock.
FireWire 800 is backwards compatible with the original FireWire 400, but to plug an 800 device into a 400 controller you need to get a cable with a 400 plug on one end and an 800 plug on the other.
WiebeTech, sensibly, include just such a cable with the ComboDock. You also get one world-compatible power adapter, one neat hook-and-loop-closure wallet to protect the Dock from damage when it's not in use, one screw-on baseplate to guard the electronics on the bottom of a hard drive, and some stick-on rubber feet. You also get a decent set of paper instructions.
Rather stingily, WiebeTech have chosen not to include a USB cable. Since the ComboDock uses a mini USB socket, the regular A-to-B cables that many USB addicts have on hand are no good. A-to-mini USB cables are easy to get, but it still would have been nice to see one in the package.
The ComboDock kit also doesn't include a FireWire-800-at-each-end cable, but that's understandable. Even in the Mac world, not too many people have 800 yet.
Here's the ComboDock on a drive, with the older Super DriveDock next to it for comparison.
The ComboDock is a bit easier to attach to a drive than the Super DriveDock, because its ATA plug isn't framed by metal, so you don't have to jam the power plug in if you've got a drive with power and data connectors close together. It's not quite as sweet an arrangement as the sliding power plug in the SNT box, but it's good enough.
The ComboDock also has a little cushion above its connectors, which is upholstered with fine metal mesh. The cushion firms up the mechanical connection a bit, and was (I'm told) required to give the Dock's chassis a clean electrical connection to the casing of the drive, allowing the combination to pass as a Class B device according to Part 15 of the FCC Rules.
I tested the ComboDock with the same 250Gb Western Digital drive I used when I checked out SNT's drive box yesterday.
In FireWire 400 mode, the Dock's performance was pretty much exactly the same as that of the cheaper SNT box. On average, 86% of the speed the drive managed when connected natively to the motherboard's ATA controller.
I don't have a FireWire 800-equipped machine here, so I couldn't test its speed with that interface. There's not much room for it to be faster, though; 86% of full speed is already close enough that you wouldn't notice the difference for pretty much any normal desktop computer operation, and there's no way FireWire 800's going to be faster than the drive's native performance.
In USB 2.0 mode, the Dock outdistanced the SNT box by a measurable, but not important, amount; it managed 79% of the drive's native performance, versus the 74% the SNT box managed.
I didn't test the ComboDocked drive in USB 1.1 mode. It works. Its transfer rate sucks. That ain't the ComboDock's fault; USB 1.1 is not the choice of champions when gigabytes of data need to be moved.
And now, nitpicking.
I find those results highly suspicious.
Bare Feats were testing two striped Maxtor DiamondMax Plus 9s (of unspecified capacity...), using QuickBench, a benchmark utility that runs under Mac OS X and, as I understand it, does operations with real files.
That's a good way to get realistic numbers. But real-file testing should give significantly lower megabytes per second than the drives can deliver when they're just feeding an I-don't-even-need-the-drive-formatted raw transfer rate test utility.
Somehow, Bare Feats got two of those drives in a striped array, through FireWire bridge hardware, doing real filesystem transfers, to deliver a read speed of 111Mb/s. That's 93.75% of twice the maximum raw transfer rate, which strikes me as very implausible.
I've no doubt that this setup is indeed fast, but I'd like to do a good old fashioned stopwatch timing of a ten gigabyte single-file read-to-/dev/null operation to see if it actually took only a minute and a half (yanking the cable at the apparent end of the test, to see if a buffer somewhere's playing silly buggers, is optional).
I don't think they were even using a hardware RAID controller, for Pete's sake. Even hardware RAID will never deliver twice the base transfer rate of a single drive from a two drive array (though good controllers can get close), and software RAID will eat even more performance. Mac OS X is cool, and all, but it ain't magic.
Wiebetech assure me that Intech SpeedTools has reported 55Mb/s for the outer cylinders of similar drives, and 105Mb/s for two of them soft-RAIDed, on a Power Mac G5.
Well, OK, if they say so - but I really don't know where all that data's coming from, when the overhead of interface bridging, software RAID and a filesystem is taken into account.
The ComboDock's screw-fastened anodised aluminium casing is very robust, yet easy to open. So I opened it.
Inside, there's a tidy two-circuit-board arrangement - one board for power, one for data. The data board is equipped with a Texas Instruments TSB81BA3 FireWire transceiver, and an Oxford Semiconductor OXUF922 (PDF datasheet here). That's the main muscle chip - it's a FireWire and USB bridge. Linux driver hunters may need to ask for the OXUF922 by name; users of vaguely recent Windows and Mac OS flavours can, of course, just plug and go.
WiebeTech know that you can get whole external drive boxes for rather less than the price of one of their Docks. At $US169.95, the ComboDock's not way more expensive than a decent dual-interface enclosed box, but it does cost more - and you may need to buy a USB or FireWire 800 cable to go with it.
But if you want a normal external drive, you don't want an AnythingDock, with or without the screw-on protection plate for the drive base. With the best will in the world, a friction-fit Dock plugged into the end of an un-cased drive is not a very sturdy storage solution.
The advantage of the ComboDock is the same as the advantage of the earlier DriveDocks - it lets you interface-bridge any bare ATA drive in seconds, and swap the bridge to any other drive just as quickly.
It doesn't even matter if the drive's still installed in a computer chassis. As long as there's a bit of clearance behind it to plug in the Dock, you can turn it into a USB or FireWire device, hook up a whole different desktop or laptop computer to it, hoover data off it at warp speed using the interface of your choice, restore everything to its previous state, straighten your bow tie, and return to your competitor's office Christmas party with no-one the wiser. The only screws you'll need to undo are the ones holding the side of the case on.
(And yes, Mac owners, I'm aware that there might not even be that much fuss.)
For its chosen purpose, the ComboDock is a great piece of gear. I wouldn't mind if it came with another cable or two, and I'd like to see a standard Type B USB socket, and the FireWire 800/400 plug difference thing is a bit of a pain - not that you can blame WiebeTech for that.
But this is just nitpicking. The ComboDock is better than the DriveDock, and the DriveDock was already good. WiebeTech Docks aren't for everyone, but for some people they're worth their weight in something that's worth a lot per gram.
Review ComboDock kindly provided by WiebeTech.