I've known about this for years, as you get so much package loss on wi-fi due to interference from tv's, fridges, etc, which is why I instructed Rayna to use cable whenever possible.
People relying on home wi-fi are getting significantly slower speeds than from their fixed broadband connection, research suggests.
The study ran one million tests over 14,000 wi-fi connections in the UK, US, Spain and Italy.
On average, the results showed a 30% drop-off compared to the speed coming into the home.
http://www.bbc.co.uk/news/technology-12688839