Product Reviews

If you've installed a wireless network in your home or office and not had any problems with coverage or speed, you're one of the lucky ones. Dividing walls and multiple floors can prove a real challenge for 802.11b/g wireless, especially once you start looking at media streaming or moving big files reliably around the network. Power-line networking is nothing new, but the increasing interest in streaming media has given it new impetus. With the mains wiring in your house already relatively robust and neatly integrated, power-line networking could be just the answer you're looking for.

To test the three sets here - Panasonic claims transfer rates of 190Mb/sec, and Netgear and Devolo 200Mb/sec - we installed each pair in a high-rise London flat, measuring real-world speed by copying 185 digital photo files from one PC to another (averaging 2MB each), as well as streaming HD video and monitoring for glitches. To test resilience to sources of interference, we repeated the tests while running a microwave.

Costing £97, the Panasonic HD-PLC Ethernet Adapter is reasonably good value, and also held up well in our speed tests. Setup takes just a few seconds - plug both devices in next to each other and they pair automatically. You can then split them up and use them throughout the house. With our devices installed and both computers recognising each other straight away, we managed to stream HD 720p video over our network flawlessly. Even running two streams of video concurrently resulted in only minor stuttering in the second stream, while the first continued to run perfectly.

The HD-PLC managed just over 2MB/sec in our file-transfer test, and that was unaffected by plugging them into a four-way power strip (against Panasonic's recommendations for good performance), along with a couple of phone chargers.

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Problems only occurred when we ran our HD video and began transferring files, producing unwatchable stuttering video, and decreasing the file transfer speed to a shade under 2MB/sec. The lack of HomePlus compatibility - the only industry-wide standard for power-line Ethernet products - is a shame too and ultimately costs the HD-PLC an award.

The Netgear HD Ethernet Adapter HDX101 provided an altogether different experience. Sharing an internet connection proved acceptable, but our other tests were too challenging. Even with both devices installed in the same room and plugged directly into the wall, we couldn't run our 720p footage with any measure of success, while a DivX file with a considerably lower bit rate ran poorly. After taking a laborious 22 minutes to transfer 100MB of files, we simply gave up on the remaining 900MB. We saw equally disappointing results after installing and configuring the supplied software.

We're not wild about the form factor either, as the plug itself is huge - just over 7cm wide - which means that on a four-way power strip it won't live happily with much else. While it's possible that the poor performance may be fixed in a later firmware update - there's plenty of anecdotal evidence from the US that some users are happy - until then it's one to avoid.

The best kit on offer, though, is the Devolo dLAN 200 AVdesk. It isn't the most attractive device in the world, but it's a superb example of a product that simply works. In our tests, there was no need for any initial setup at all - our devices obtained IP addresses just seconds after we plugged them in. A set of status lights on the front panel lets you know the status of the device. Satisfied that our network was working properly, we were thoroughly impressed by its performance. Two streams of HD content worked with just occasional stuttering in the second stream.

We transferred our 1GB of files in just over six minutes, or 2.7MB/sec. Transferring files while streaming the video produced a notable decrease in video quality, although our file-transfer rate remained much the same. Introducing electrical interference had little effect either, indicating some robust interference algorithms. The only drawback is that Devolo's devices are around £20 more expensive than Panasonic's almost equally fast pair, but it scores major points for HomePlug compatibility and so it wins our recommendation.