Need some help with a "Tweaking" Program

I recently built a computer with 2 8800GT's and I found that the video cards come with the fan stayed at 28-29%......so i downloaded rivatuner to fix that.

When i downloaded the program, I turned the fan speed to 70%, except only ONE of my video cards decreased in temperature. I'm assuming that only one of the video cards has increased fan speed, how can i make both of them have a boost?

Any comments are appreciated

Thanks