How to get my second graphics card to activate on power on?

So in my system I have two 7870s not in crossfire (i need the outputs) but when i boot up i only see my main display (on card 1) come on, and not my other ones (on the second card). So does anyone know how I can get both cards to come on, before windows boots?

I just added a second 7950 and on my Asus P8P67 mobo I had to go into the BIOS and set the PCIe to 4x instead of auto to enable the second card. I'm really just guessing here (pretty noob myself on the subject) but you might want to look in that direction. 

That didn't work, i have this mobo>

On my Z77 board it never activates on power on, I have to put my gpu's under load first with a full screen. I think it is a power saving feature. I just added a second 7870 to my pc.

by not come on do you mean the light on the card isnt showing up or windows doesn't recognize it

I mean when i press the power button, my main display (the one on card 1) comes on but not my second or third (both on card 2) is there anyway to get all of the displays to come on at the same time?