I have been working on a review of the SlingLink for a while and it struck me that it would be best to have a similar HomePlug device for comparison and interoperability testing. I managed to obtain a Solwise HomePlug PL-85PE with which to do just this. What follows are my findings.
HomePlug is a networking solution that allows you to use your existing household power cables as network cables. To establish a network connection between one room and another you simply plug a HomePlug compatible device into each room and it just works.
You can use HomePlug devices directly between a cable modem (I used my Virgin Media, ex NTL one to test this) and a router, between two computers, between a games console and a router or any other situation in which you would ordinarily use a long network cable.
Unlike the humble network cable, however, HomePlug will act like a hub and support multiple units throughout your house connecting far more than just two devices together into an extensive, seemingly wireless, home network. There’s also no need to drill holes and route cables, they really do just plug in and work.
First and foremost I would like to get the physical benefits and/or drawbacks of both devices out of the way. SlinkLink comes as a box with a separate plug meaning it can be plugged into the wall and stowed away inside an A/V cabinet, very fitting considering it was designed to be used with the SlingBox.
The Solwise HomePlug PL-85PE, on the other hand, is an adaptor that plugs into the socket in its entirety and has a network port on the bottom. This is a nice tidy solution but prevents you from plugging it into an extension socket. You’re technically not supposed to do this with HomePlug devices but they still appear to work, even when connected through two daisy-chained extension sockets- not that I, eerm, recommend such obscure configurations.
HomePlug to SlingLink
For the first test I decided to take the plunge and see if the Solwise PL-85PE and SlingLink would play nice with each other. They got the better of me, of course, and establishing a network connection between the two different devices was literally as simple as plug and play.
Between these devices I found a low ping of approximately 2.3, with some very dramatic peaks reaching 130ms and even a single packet lost in the power-line ether. The average ping was all over the map ranging from 10ms on my first test down to 4ms on my third.
I was surprised at these initial results, fearing that the HomePlug devices were severely underperforming. I had a small stroke of inspiration when I realized that I had a second SlingLink plugged in and turned on upstairs that may be interfering with the downstairs connection but disconnecting it had absolutely no clear effect on any of the ping statistics.
It seems all too clear, however, that these flaky initial results both show up the slight ineffectiveness of using pings to test networking performance in addition to the incredible variation in performance that can occur when trying to cram a network into your household power infrastructure. Further tests showed much more promising and acceptable results, but certainly nothing groundbreaking- although HomePlug doesn’t set out to set any speed records, focussing instead on a huge level of convenience. This is especially important in older houses where cinderblock walls don’t do wireless any favors.
HomePlug to HomePlug
Using the Solwise HomePlug PL-85PE at each end of the power-line network link I conducted the same test as above. On average I obtained a ping of around 3.4ms with a low of 2.3ms and a high of 24ms. A definite improvement over the original results that, if it is to be trusted, shows quite clearly that identical devices offer a much better connection than disparate ones.
SlingLink to SlingLink
As above I again conducted four tests using the SlingLink, with varied results. Each test revealed a low ping of approximately 2.3ms, an average of between 3.1 and 3.4 and a maximum ping of 43ms.
In order to effectively gauge how HomePlug sits in the networking world I performed the same 100-ping test over draft-N WIFI between my MacBook Pro and the AirPort Extreme Base Station. The results were staggeringly lower than those of the HomePlug device, with a max ping of only 4ms – not far off the HomePlug minimum.
The minimum ping over WIFI was 0.4ms with an average of about 1ms. Over wireless I encountered absolutely no dramatic latency spikes. Presumably these are accounted for in the HomePlug system by the varying conditions of your power lines, but I can’t do more than hypothesize on the cause of such dramatic spikes.
Not entirely surprisingly, none of these results show a large enough difference to place the SlingLink or Solwise HomePlug devices over one another in terms of performance.
What the results did reveal, however, was a slight lack of performance in the HomePlug technology which can most likely be accounted for by the less than ideal wiring which they use to establish a connection. In many real world situations this less than stellar performance means very little and HomePlug is more than capable of facilitating network media streaming. In a gigabit ethernet and Draft-N wireless environment, however, even the 200Mbps HomePlug is theoretically a bottleneck and should be employed only where speed is not essential.
On to the throughput testing.
Both the SlingLink and Solwise HomePlug PL-85PE use 85Mbps chipsets. This means that they can theoretically, in the best of circumstances, attain an 85Mbps link speed but this is very unlikely to be achieved in your home. Connections to the HomePlug devices are reported at 100Mbps. However, this only accounts for the network cable between your computer and the HomePlug device.
In order to test the actual link speed and throughput of the 85Mbps HomePlug chipset I initiated a file copy from my system to network storage connected directly to my router. With the information gathered from this copy I was able to unscientifically estimate my link speed at just over 60Mbps. Not too shabby for something rated at 85.
I would like to have identified a definitive winner, but the fact is that neither the Solwise HomePlug PL-85PE or the SlingLink can be considered as such. Ultimately the SlingLink is much better for use with the SlingBox as it can be stowed tidily away in an A/V cabinet, although Solwise produce similar solutions they aren’t nearly as pretty.
The HomePlug PL-85PE is slightly different and needs its own wall socket or it’ll render at least one additional socket on an extension board useless with its bulk. If you do have a wall socket handy it’s an undeniably tidier solution and is cheaper.
Finally I would like to re-iterate that, although I got slightly scientific in my testing of these HomePlug devices, that the emphasis here is on convenience and ease of use instead of high performance. Both the SlingLink and Solwise Homeplug PL-85PE manage to satisfy these demands with flying colours, are as easy to set up as plugging in a network cable and seem to just work!
The Solwise HomePlug PL-85PE can be had for about £50 and the SlingLink can be had for £59.99 delivered at Play.com. Both of these packages contain two units, but most Solwise units can be purchased separately to expand your network at your own pace.