Eight months have passed without any clock speed increases in AMD's Athlon 64 family. One reason why AMD stopped at 2.6 GHz certainly was that the 130 nm production process was reaching its limits. Another was the certainty that main competitor Intel had to operate even closer to the limits that its 90 nm process burdened the Pentium 4 family with, so there was less urgency for AMD to up speeds further. These circumstances will persist for a while, meaning that the FX-57 will basically compete only with its own predecessor.
This is the first product update that introduces new technology since the high-end FX offspring of the Athlon 64 family was introduced. While the preceding FX CPUs were based on the 130 nm Clawhammer core, FX-57 is a San Diego core product using a 90 nm process. It is expected to deliver more performance without pushing the thermal envelope any further.
Three 90 nm cores have been around for a while now. The Winchester was the first 90 nm part (512 kB L2 cache, up to 2.2 GHz at 67 Watts thermal design power) and actually managed to decrease heat dissipation at low and medium clock speeds. Today, Venice (512 kB) and San Diego (1 MB) are the cores of choice, since they not only replace the old Clawhammer and Newcastle cores, but also feature SSE3 extensions that are important to have for certain professional applications. In this context, it is pretty interesting to know that AMD derives several Athlon 64 and Athlon 64 FX models from these two cores.