Good downstream speed for watching movies/tv online?

What is the lowest plausible downstream speed if I want to use my internet connection to watch movies and tv online?

My choices are 1.5 mbps, 3, 6, 12, 18 and 24.

It depends on many factors. Full-screen or smaller? Are you using generic software like Windows Media Viewer, or proprietary like Netflix?

1.5mb/sec should be fine for most cases. Netflix will downgrade the stream but keep you viewing if it can’t keep up; other viewers may stop & start.

But are you sharing that pipe with other users or apps?

As a reference point, in a test I did at 256Kb/sec, I was able to (barely) watch 320 x 200DPI, 30fps video. That’s a long ways from full-screen or DVD quality, though. Double each dimension and you quadruple the data, all other factors being equal. DVD is about 720 x 480 and compression varies.

For one data point, I have a pretty boring but consistent (if not reliable…) 3 mbps DSL connection from Verizon. I use it to watch shows via Netflix and a handful of network sites (NBC, Comedy Central, etc.) Netflix streaming works great, though video quality isn’t perfect – definitely less than DVD quality. Resolution is pretty good but there are sometimes noticeable compression artifacts. However, playback suffers greatly if I’m trying to download something while watching.

I can watch video on other streaming sites acceptably, though some sites will hiccup since they seem to expect a higher speed connection. Comedy Central in particular has less than stellar playback.

I’d recommend 3 mbps as a minimum starting point. It’s good enough, but not amazing. I sometimes think of upgrading to the 5mbps connection, but I’m not sure it’s worth the extra money…

1.5 mbps is the minimum non buffering speed because with the newer common movie files my connection at half that speed requires twice the time to download to buffer as it does to play. I would get the 3 mbps to watch movies as there will be some extra bandwidth.