The Short Version: My Apple TV (2nd gen) downloads were requiring far more time than necessary. I narrowed down much of the problem to a setting on my Apple Airport Extreme Base Station. By switching it over to “802.11a/n – 802.11g/b” from “802.11a – 802.11g/b” I noticed an immediate and significant improvement. 

A little while ago we tried to rent a movie from iTunes to watch on our 2nd generation Apple TV. The download was agonizingly slow. On average the load time showed it would be one and a half hours before the movie would be ready to watch. Obviously, this was an issue and made even more annoying considering it was already past 9 PM on a weeknight.

To make a long story short, I made three changes and though I’m not absolutely positive which one actually made the difference I think I know which change worked.

I came across several posts where users had improved their download speed by changing their custom DNS settings to instead use their ISP provided DNS servers. That did match my situation so I went ahead and set the Apple TV to use my ISP’s DNS. However, that didn’t seem to make a difference.

I also changed the iTunes rental preferences to only download SD (instead of renting HD when available). Considering I had already started the download of whatever format was available for the movie I don’t think this change made a difference and I may go ahead and set it back.

The one change that seemed to make an instant difference was to change my Apple Airport Extreme Base Station to use “802.11a/n – 802.11g/b”, instead of the “802.11a – 802.11g/b” configuration that it was apparently set to. This probably was the problem considering that the Apple TV does support 802.11n. Perhaps it just wouldn’t work properly on the wireless without 802.11n support enabled.

Updated 06/27/2011: Ever since I made these changes the rentals have started immediately. We’ve rented two TV episodes and three movies and all have worked great. I didn’t set the quality back to HD. Everything I’ve viewed has looked great at the SD setting and usually saves about a dollar per rental so I haven’t bothered to change it back.