The HD stream is a variable compression so your question only is the opening question to the age old "how to move video" across the internet?
The HD shot of the Polar bear in a snowstorm is used to start off that such a shot in HD could arrive in a split second. So almost any connection will do.
For your research.
Ok, With the new xbox 360 update comming out soon with the ability of instant on 1080p, I was starting to wander if my Internet can download that fast. At the current moment I have about 1411 Kb/s download and 474 Kb/s upload. Does anyone know what the absolute minimum speed for 1080p and netflix HD streaming. If my current speed isn't fast enough the highest I can go is 3 Mb/s down and 567 Kb/s up. Thanks in advance