Underclocking GPU Due To Noise (Case Fan Questions)

So I have a MSI R7950 Boost OC GPU

 

I found that I have had to underclock it because I really don't like the noise levels it's producing it's not sooo bad but it is still quite annoying I feel like if it was a bit a cooler I wouldn't have this problem. In normal gaming gpu is about in the mid 70s around 75 I think is when the fan hits uncomfortable noise levels but when I went back to tombraider it hit 81 which is pretty bad. So My case is a zalman z11 plus. When I bought the case I wasn't really aware of the whole positive and negative pressure thing. Here is a picture of the case and it's fans

You can't actually see it in these pictures but there are 2x exhaust fans, one in each side panel as part of Zalman's unique HDD cooling solution demonstrated in the following picture.

eAZHq9B.jpg

Is it just me or is this crazy negative airflow. There is one intake... Then two exhausts in the side panel and another two exhausts one in top and one in the rear. Could that be what is causing my bad gpu temps. So anyway on to the main question. If you go back to the first set of pictures where it shows you the fan options if you look at the small pictures the one at the very left you can mount a 140-120mm fan in the bottom for a filtered Intake

 

Now I take it allot of the intake fans air is being taken up by the two fans in the side panel but this fan would be literally pointing at the gpu. Now I plan to put to a 140mm fan here. Just so I know if it's worth it for a rough estimate how many degrees do you think that would help the gpu. I think it should help a bit as if you look it would literally be point at the gpu

 

Also two more additional question

So the fan I'm going to be using is the Aerocool Dead Silence 140mm fans. At first I was thinking the AF140s which do 67.8 CFM which is good airflow and in terms of noise 24 DBA

But then I found the Aerocool Dead Silence 140cm Fans which do 64.8 CFM which is almost the same but at 14.4 DBA

and I have never seen a sexier fan here is a pic

 Do you have any other recommendation?

 

and onto the second question I always keep the default fans of the case so I've never actually mounted one so from some research I'm pretty sure I mount it with the back of the fan, the side with the bracket looking up at the graphics card if I want it to be an intake. But which horizontal direction are you supposed to mount it does it matter do you just mount it where the cable is easiest routed?

Thanks so much

What GPU, and could you not just tweak the fan profiles for the GPU in MSI Afterburner, rather then underclocking?

Lol the gpu is literally the first thing I say. Although I guess I do leave a big gap so you probably didn't see it. Anyway I have the MSI R7950 Boost OC

and I really wouldn't be comfortable with it running any hotter than it already is

I would say try tweaking the fan curve in MSI afterburner before underclocking (undervolting included I assume)

you might be surprised how quiet it might stay if you let it climb higher in temps before letting the fans really ramp up.

Also, the way air flows through the case plays a huge role in controlling temperature. I would say look at your case and how things sit in the case, and set up fans in way that makes sense. intakes where you need fresh air and exhaust where hot air congregates.

As I said I wouldn't like my GPU to be any hotter. I have looked at my case and there is only one place another intake can be put + it's pointing at the gpu so it seems pretty logical