6870 vs. 6950 Noise comparison

[ZGrip]

I am considering upgrading my current HD 4850 512mb to something a little more up to date.
Currently my 4850 has a tiny little blower in it that makes a hum which drives me insane at anything above 40% fan speed. I am looking for a card which is more powerful and makes considerably less noise, or at least a card which doesnt "whine" like my current card.

My current specs relevant to video card:

phenom II x3 @ 3.5Ghz
4GB DDR3
radeon HD 4850 512
corsair HX 520 PSU
1680x1050 resolution

I was looking at an XFX 6870 Dual fan for its near silent cooling but it kills me that a 6950 1GB is only 20-30 dollars more AR.

Does anyone have any guesses as to the noise and performance difference between the two at my resolution and with my setup?

Thanks

 

[Castiel]

Considered the 560? I have a MSI 6870 Twin Frozr II and its whisper quiet but overpriced.

 

[ZGrip]

While the 560 is enticing I will most likely stay with AMD for now.