Will the AMD RV790 Architecture be Something Different?
 

Current estimates point to both AMD and NVIDIA releasing a more midrange part on TSMC’s newly opened 40 nm process. Initial reports peg this process as being somewhat problematic. While the die shrink aspects are nice, apparently TSMC did little to improve the underlying materials used in their 40 nm process. Leakage is a major issue because of the lack of improvements in these materials combined with the finer geometries (stuff being closer together). In comparison companies like Intel and AMD have invested a lot of time and effort into the materials so as to improve switching speed and decrease leakage. AMD uses SOI, both AMD and Intel use Low-k di-electrics, both use compressive and expansive strain technologies, and Intel has also introduced High-k/metal gates. All of these technologies act to decrease leakage and improve transistor switching speed/power. From all indications TSMC has not changed the materials from 55 nm to 40 nm in any significant way. In fact, performance could be slightly worse overall for the 40 nm process as compared to 55 nm, even though the die savings may outweigh some of these performance considerations.

http://www.pcper.com/article.php?aid=675