Noise is a factor and My rez 2560x1600.....I just had a one of my trusty 6950's die on me and the replacement 670 ftw died in 3days and don't now which card to get anymore honestly....
For high resolution, you want 7900 series. The MSI TF3 is decently quiet at below 50% fan. If you want really really quiet cards, your best bets are:
*Not in any particular order*
1) Sapphire Vapor-X 7970
2) Sapphire Dual-X (but #1 is better)
3) Asus Direct CUII 670/680
4) PowerColor PCS+ 7950
Here are the noise levels for 7950s --
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Here are the noise levels for 670s --
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Here are videos for noise levels of 670s --
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Here are the noise levels for reference AMD and NV cards --
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Here is how current performance stacks up --
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