As for the R520, it seems to be facing the same sort of leakage issues at 90nm that have plagued Intel's Prescott Pentium 4 processors:
ATI is currently revamping the chip design of its R520, said the makers, adding that the company is facing leakage issues, as it attempts to migrates its manufacturing to a 90nm process. The situation is similar to when Nvidia postponed the availability of its 0.13-micron NV30 high-end chip in 2002 due to production issues, the makers pointed out.Fab process risk is a tricky beast, indeed. However, DigiTimes' loose-lipped mobo-maker sources say that "ATI may launch its mainstream R530 and entry-level RV515 GPUs ahead of schedule, with both parts being manufactured at 90nm." These smaller GPUs with more modest performance targets may be less affected by the leakage problems hampering R520.