I mining LTC, but posted here because the type of currency irrelevant anyway.
I recently saw somewhere in a forum how to undervolt the 7990, but can not find that post now. I just remember that I have to change some values in registry to zeroes, copy dll to afterburner directory and so on.
I will really appreciate if somebody would give me a link to that post or just let me now what I need to do.

The card I bought makes easily 1200 and more despite I lowered GPU and memory clocks, so I want to undervolt it to keep temperatures in the range I am feel comfortable with.

Thanks in advance.