Sun is continuing to tweak its "Galaxy" line of Sun Fire Opteron-based servers to they can support the new "Santa Rosa" Rev F Opteron processors from AMD . "The initial Galaxy boxes from fall 2005 were based on the Rev E iteration of the Opteron chips, which come in a 940-pin package. The Rev Es have an integrated DDR1 main memory controller on the chip. The Rev F chips come in a 1207-pin package that has a completely different processor socket and, because they also support DDR2 main memory, they also have a different main memory controller on the chip. What this means is that even though the cores in the Rev E and Rev F processors are essentially the same--the other big change is that the Rev F chips support the hardware-assisted virtualization feature code-named "Pacifica" and now known as AMD-V--the server boards that Sun created for the Galaxy line have to be changed to make use of the new Rev F processors. AMD has also created a modified 940-pin variant of the Rev F Opteron chips called the AM2 socket for entry servers and workstations."