I've got several Saphire OC 7870s ( http://www.amazon.com/gp/product/B00A2J4ROE/ref=oh_details_o00_s02_i00?ie=UTF8&psc=1 )

I'd like to undervolt them, while there's a bunch of info in undervolting 79xx, I haven't found much related to 78xx. My first concern is increasing the life of the cards, and second saving a little power. Unlike other cards, I haven't been able to find a BIOS switch, I'm pretty sure they don't have one. I'm little concerned about bricking them.

Outside of general undervolting advice from tutorials like cryptobadgers, does anyone have any advice?