I have a 3-way crossbridge for my 7970. When its in idle i get 39c when I play BF3 my temp seems go up steadily to about 100-110c not sure if that's normal or not. I use gpu-z to check my temp. Any help would great and appreciated.
How many fans do you have in your case and how are they oriented?
If you just have 1 7970, at its factory clocks, with decent case ventilation (front intake, rear exhaust, and one of either a side or top fan), then you should check to see if the cooler is sitting properly on your GPU die. It has a lifelong warranty anyways so you can always RMA it. But the custom cooler dumps all the GPU heat into your case, so if you have poor case ventilation (which has more to do with your fans than your case chassis) then the card can overheat.
If you have 3 Black Edition 7970s, you probably need a 120mm side fan either blowing air down on them or exhausting their hot air. You'd have to test which way helped your temps more... I'm not sure with the custom cooler which way a side fan should go.
Basically, without side ventilation, you have 3 cards just crapping heat all over each other since they don't exhaust out the back of the case.
You need high performance front intake, side (intake/exhaust?), rear exhaust, and top exhaust fans to get enough airflow through your case to deal with the heat from 3 of those cards.
:edit: Just looked at your case... WOW that thing supports massive fans. You should get the biggest fans you can fit and just make sure you have front/side/rear/top all used.