Question / Help Windowed Mode Question.

[Animalistictv]

Hello, I am trying to get a good quality stream going and i was wondering if my monitors native resolution is 1920x1080 but i am playing in a 1600x900 window would this be helping my cpu by going to a lower res or am i giving it more work to do since my desktop is up in the background at a higher res?

This was my latest stream test http://www.twitch.tv/animalistictv/v/14695246

Thank you in advanced for tips.