The terms HD and UHD are nasty and misleading. HD refers to anything that's 1080p resolution, the problem is even a movie that's been 'upscaled' to 1080p from a 720p source would still qualify as HD even though the quality will be poor. Likewise the term HD takes no account of the bitrate of encode so you will find mkv containered HD 1080p movies that range between 1.6 gigs and 50gigs in size and again the playback quality will be poorer for the small file even though both are technically 1080p resolution.
I'm not sure what standard netflix encodes follow or what filesizes HD and UHD movies would be so I can't comment on ADSL speed requirements. They do have a guide on their website though.
Did you like this article? Share it with your favourite social network.