The dLAN 500 AVplus HomePlug Starter Kit is a twin pack of powerline networking adapters that promises transmission rates of 500Mbps using the HomePlug AV standard. This is an improvement on older HomePlug AV equipment that was supposedly capable of 200Mbps.
However, with many networking products, the manufacturer's performance claims should be taken with a pinch of salt. Wireless routers rarely allow their advertised speeds, as interference and thick walls drastically reduces their range and throughput.
Powerline networking isn't affected by these obstacles, but it still gives very mixed results. The quality of wiring in your home and electrical noise emitted by other mains-connected devices can have a detrimental effect on performance. Sometimes, just plugging an adapter into a different wall socket can make a big difference. See all Wi-Fi/networking reviews.
There are some installation issues with them too. The size, shape and orientation of the adapter restricts where it can be used, since it may not fit into a low-mounted wall socket. Adapters are best plugged directly into the wall, but you're stuck if you only have a single socket for your entire PC, presumably with the monitor, speakers and other devices trailing off an extension cable.
Devolo solves this problem by providing a pass-through electrical socket in each dLAN 500 adapter. You can plug other devices directly into it, including long extension cables. We also applaud Devolo's inclusion of a standby mode that means just 0.5W of power is consumed when not in use, a green effort that we're seeing increasingly with similar devices. See also: Group test: what's the best wireless router?
For the best performance, the dLAN 500 should be used with a Gigabit Ethernet network. If any device in the chain is only capable of 100Mbps Fast Ethernet, including the computers at either end, then the dLAN 500 can only perform at that speed.
We tested the adapters with one plugged into a wall socket next to the router, and the other plugged in upstairs next to a PC. We used a NAS connected to the router as an FTP server, transferring a 10GB file to and from the device. Over a wired gigabit ethernet connection, we had measured transfer speeds in excess of 600Mbps from this NAS, so were satisfied it wouldn't restrict the dLAN 500's transfer performance.
Early results were disappointing. We measured read speeds of 104Mbps and write speeds of 120Mbps, far slower than what the dLAN 500 AVplus was supposed to be capable of. The house used to test the adaptors was built in the 1930s, and despite the electrics being given a clean bill of health, we figured that a more modern building may allow better performance.
So we tried the same test in a new-build flat, with more up-to-date wiring. As expected, the results improved significantly. We measured 192Mbps when reading a file from the NAS, and 184Mbps when writing to it.
This may be an excellent real-world result for powerline networking, but is still significantly below the speed on the box. In this respect Devolo is simply following the industry trend in advertising powerline performance that simply is not possible in the real world.
Fon non-Windows computers, be aware that Devolo does not provide firmware upgrades for the Devolo dLAN 500 AVplus Starter Kit.