

Putting terabytes of memory into servers, the cheap way - edw519
http://news.zdnet.com/2100-9584_22-6231810.html

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xirium
The value of adding vastly more memory in a server is obvious. However, could
someone explain the problem that required solving by a team of 20 people?

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wmf
Chip design is hard. Measure twice, cut once.

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xirium
We've got one article ( <http://news.ycombinator.com/item?id=123263> ) in
which memory controllers are being brought on-die to increase speed. We got
another article ( <http://news.ycombinator.com/item?id=123158> ) which
describes adding another tier of memory controllers to increase throughput.

The latter could be hard to design if you were retro-fitting a tree of
pipelined memory controllers and you were concerned about interoperability.
However article makes it look like an attempt to bodge extra address lines.

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wmf
I think it's more about extra chip selects and reducing bus loading. AFAIK,
standard DDR2 memory controllers only support so many ranks on the bus, so
MetaRAM introduced some muxing to make four or eight ranks look like two. It's
a clever hack.

