[Hardware] Graphics card stress

[HundertzehnGustav]

okay, here is one...
i finisted my certification as a IT youngster this summer, and have 3 years of solving pooter problems under my belt.
Or User problems. whatever.

here is the situation-
I got SHIII back in 2005, and had it running on an ATI X1650 for 3 years.
I later ran it on a Gforce 9800... i think thats what it was called.
(machines from the past...)

Nowadays i run an ATI6970 with Drivers from October 2012

...and the card heats up to 75°, with the fan spinning like mad making an awfull lot of noise - just the sub somewhere in the sea.
noise is so bad, its completely unacceptable.


I scratch my head:
Why the hell is that so?

hardware
-is the screen resolution to do with this ? (1920 x1200)
-shutting down the second monitor (1280 x 1024) makes 2° of difference
-toning down the quality in the Graphics panel makes no difference

software
-be that GWX, be that a bog stock 1.4b - no difference
-is the resfix responsible? (activated or not... no difference?)

I need to get rid of this noise, because this is deafening.
None of my other games (sailing, [combat]flight sims, psycho shooters a la GTAIV...) heat the GC as much as SHIII.

I don't see a cause, and i don't see a solution.
If you have a clue, please say something...



(edit)
normal temps:
Both Monitors on; surfing the web = 35° / HD video replay = 41° / IL2 1946 modded to death in heavy combat = 50° / GTA 4 = 53-55°