john-users - OpenMP vs lots of cores

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Date: Wed, 30 Jun 2010 09:55:42 +0200
From: "Magnum, P.I." <rawsmooth@...dband.net>
To: john-users@...ts.openwall.com
Subject: OpenMP vs lots of cores

I haven't had the time to try the OpenMP stuff but I sure will. How far 
will it scale in the current versions? I mean, what if you had 96 cores 
on a single host? It won't use all of them, right? Or would it, given 
enough what? Hashes? Salts? I suppose even if it can use all of them, 
the overhead will at some point make it ineffective, perhaps even just 
slow it down.

Obviously though, MPI and MP could be used together. Say we have 96 
cores and fire off 12 MPI nodes using 8 MP threads each. Naturally some 
testing would be needed to find the best mix.

thanks
magnum