Q: how do I chose a lower tv resolution to down load a movie quicker than 31/2 hours?

Hi vivian184,

Welcome to the Support Communities!

The article below may be able to help you with this.  Click on the link to see more details and screenshots. 

Apple TV (2nd and 3rd generation): Troubleshooting playback performance

http://support.apple.com/kb/TS3623

Switch between High Definition and Standard Definition

If your Internet connection is slow or High Definition movies or TV shows take longer than normal to start, try changing your Video Resolution to Standard Definition. From the main iTunes menu, choose Settings > iTunes Store and switch 1080p HD or 720p HD to Standard Definition. Your Movie and TV show purchases and rentals will now be in Standard Definition.

Cheers,

- Judy