[cluster-l] Single- vs. Dual- vs. Quad-core CPUs

[Ricky Robertson]

hi nils.

this is ricky from hydro/ag-econ. my experience (on ncsa's tungsten and a scavanged mini-cluster we put together in ag-econ) has been that the memory bottleneck is the most important. my (non-expert) recommendation would be to go with the dual processor/dual core nodes and get twice as many of them (since they cost roughly half as much). that way you are maximizing the bandwidth between the same amount of memory and the same amount of feasible processing capability. there is always the possibility that the network traffic will slow things down, but you'll have to figure out which is the limiting factor. naturally, that probably can't be done until you build at least part of your system, meaning the decisions have already been made. :)

peace,

ricky

---- Original message ----
>Date: Thu, 22 Feb 2007 08:44:46 -0600
>From: Nils Oberg <noberg at uiuc.edu>  
>Subject: Re: [cluster-l] Single- vs. Dual- vs. Quad-core CPUs  
>To: jim Phillips <jim at ks.uiuc.edu>
>Cc: cluster-l at ks.uiuc.edu
>
>Hi Jim,
>
>Thanks for your response.  I should probably describe the 
>problem.  Our application is a computation fluid dynamics (CFD) 
>code.  My understanding of CFD codes is that they are primarily 
>memory bound.  Since the domain to be modeled is broken up into 
>chunks, during the course of a time-step in the simulation a large 
>number of messages (not necessary large amounts of data) are passed 
>between processors.
>
>We're trying to decide between the following:
>
>uni-processor quad-core Xeon 4 GB RAM ($2,300 / node)
>dual-processor quad-core Xeon 16 GB RAM ($5,800 / node)
>dual-processor quad-core Xeon 8 GB RAM ($4,600 / node)
>dual-processor dual-core Xeon 8 GB RAM ($3,800 / node)
>dual-processor dual-core Opteron 8 GB RAM ($3,200 / node)

ricky r
--
rdrobert at uiuc.edu                  Carpe faenum: Seize the hay!
rickyr at andrews.edu

Little evidence supports the claim that refined sugar intake significantly
influences behavior or cognitive performance in children.
  --J Wade White & Mark Wolraich in Am J Clin Nutr 1995; 62(suppl):242S