[Beowulf] performance tweaks and optimum memory configs for a Nehalem

[Jonathan Dursi]

On 7-Aug-09, at 7:59PM, Rahul Nabar wrote:

> Is it a bad mistake to configure a Nehalem (2 sockets quad core giving
> a total of 8 cores; E5520) with 16 GB RAM (4 DIMMs of 4GB each)?

It depends.

You'll have to do the timings with your codes; with mine (a uniform  
grid explicit hydrodynamics code; memory limited, with extremely  
regular memory access patterns) I saw a pretty robust 10% performance  
difference between a 16GB `unbalanced' and an 18GB `balanced' memory  
configuration.    You'll have to do the measurements and decide if  
the resulting performance gain is worth the cost...

	- Jonathan
-- 
Jonathan Dursi <ljdursi at scinet.utoronto.ca>