(NOTE: While this isn't a wireless product, strictly speaking, it performs much the same function, and can also be used to expand a wireless network by connecting access points together.)
It's a neat trick being able to transmit data around your home or office via the mains power wiring. You get a more stable, less interference-prone connection than Wi-Fi and a potentially faster link too. The downside is that there's no roaming, at least not beyond the reach of an RJ-45 cable and however many powerline adaptors you've got dotted around your house.
Just as Wi-Fi is due to get a major speed bump, with 802.11n, so too is powerline Ethernet. The difference: the 200Mbps powerline is here now, while the 380Mbps 802.11n isn't going to be ratified until later this year, though we're likely to start seeing a raft of standard... almost products come in the next few months.
Scenting an opportunity, makers of powerline network products are beginning to push the faster technology, particularly now that consumers are starting to ponder streaming HD video around their homes. With that in mind, Netgear last year began packaging its already-available HDX101 200Mbps adaptor as a pair of units in a 'starter kit'.
Netgear was able to get to market well ahead of its rivals by adopting a different technology. The best known powerline system, the de facto standard, is HomePlug, touted by the HomePlug Alliance. Almost everyone supports HomePlug's 14Mbps and 85Mbps standards. Unfortunately, delays to the ratification process meant the 200Mbps HomePlug AV specification wasn't approved until the summer of 2006.
In the meantime, chip maker DS2 had already started offering 200Mbps powerline chipsets by adapting an existing European standard called Opera, developed for broadband connections between homes and electricity sub-stations. Alone among powerline Ethernet adaptor vendors, Netgear chose to use the DS2 system rather than wait for HomePlug AV to be finished.
If you already have 14Mbps or 85Mbps HomePlug-based powerline adaptors in place, any HDX101s you add will happily co-exist with them, Netgear claims. But don't expect them to communicate with each other. Opera is incompatible with HomePlug 1.0 (14Mbps) and HomePlug 1.0 Turbo Mode (85Mbps). Nor is it compatible with HomePlug AV. Which, in case you were wondering, isn't compatible with the slower HomePlug specifications either but, again, will co-exist with them.
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I used two HDX101 units to connect a MacBook Pro and a Sony Vaio notebook between upstairs and downstairs rooms in my apartment. Powerline Ethernet adaptor suppliers warn against using multi-socket boards, but I had to and so, I suspect, will many other users. Avoid boards with surge-protection circuitry - that's the killer, I'm told. For testing, I used a simple two-socket extension cable with nothing plugged into the second socket.
I first used the open source network testing tool iperf to measure the link's TCP and UDP available bandwidths and got 56Mbps and 59.4Mbps, respectively. That compares to the 50.6Mbps and 59.4Mbps I recorded for the Devolo units over the same stretch of mains cabling. It's worth noting, perhaps, that when monitoring network usage with Windows Task Manager, the Devolo box produced a smoother chart than the Netgear.
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Verdict
Netgear's HDX101 is a solid powerline adaptor, but there are a couple of points to consider before buying one. I wouldn't hesitate to recommend it for performance, but there's the little matter of its incompatibility with other so-called 200Mbps products - if you want more units, you'll have to buy HDX101s if you want them to talk to each other. It's also quite a chunky unit, and it does suffer from a much slower connection initiation speed than its rivals. On the plus side they're about £20 cheaper than, say, Devolo's equivalent units.
Cost is a significant issue: The kit of two HDX101 units is $196 from Newegg.com .
A better bet if you don't need the extra speed is probably the ZyXEL PL-100 85Mbps Powerline Ethernet Adapter, normally $60 each from Newegg.com, but currently only $40 each after mail-in rebate:
Review: