http://www.techpowerup.com/reviews/A...0_Direct_Cu_II
- Cheaper than the 7970/680
- As powerful as the 7970 and practically as good as the 680
- More energy efficient than the 680/7970
- Probably more powerful in SLI than a 690 and cheaper in doing so.
Notice the sound-levels for ASUS' Direct CU II cooler and then realize it's not 3 slots, like it usually is. The "stock overclock" also seems to have pushed it's performance beyond that of the 7970/680.
Update: So 670s in SLI are 1-2% less powerful than a 690, use more power than a 690, but cost about $200 less than a 690.