Intel Corp (INTC)

[chipguy]

Also has the codename "Mill Brook" for the FBDIMM->DDR3 microbuffer.

Indeed, now that it is in the public domain it can be readily
discussed. It is clear from those diagrams that the microbuffer
concentrates two DDR3 channels into one FBD2 channel.
That gives Beckton, and by extension Tukwila, the equivalent
of 8 DDR3 channels worth of memory bandwidth per socket.

The upside vs FBD2 is cheaper and cooler DIMMs common
with commodity server space. The downside is probably
lower memory capacity per socket. My guess is thar DDR3
will be used in most 2s and 4s boxes and FBD2 will be used
in bigger, more expensive scale up machines.