[Beowulf] Nehalem memory configs

[Peter Kjellstrom]

On Wednesday 08 April 2009, Joe Landman wrote:
> As an FYI, Beowulf veteran Jeff Layton wrote up a nice article on memory
> configuration issues for Nehalem (I had seen some discussion on this
> previously).

Can anyone confirm that mixing different sizes of dimms, even when keeping to 
a by-three-symmetric configuration, actually does degrade performance?

That is, first hand information that config 1 will be slower than config 2:

1: two sockets, 3x 1G and 3x 2G per socket RDIMM (total 18G @1066)
2: two sockets, 6x 1G(or 2G) per socket RDIMM (total 12G (or 24G) @1066)

/Peter

> Link is here:
> http://www.delltechcenter.com/page/04-08-2009+-+Nehalem+and+Memory+Configur
>ations
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