[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <4255c2571003100931ud5f34dehf2ec55f2052a262b@mail.gmail.com>
Date: Wed, 10 Mar 2010 10:31:54 -0700
From: RB <aoz.syn@...il.com>
To: john-users@...ts.openwall.com
Subject: Re: Is JTR MPIrun can be optimized for more cores ?
2010/3/10 Solar Designer <solar@...nwall.com>:
>> but is also a clear indicator of the lack of communication between the
>> individual processes.
>
> Is it? Assuming that only the "incremental" mode was in use, any
> communication between the processes wouldn't make much of a difference.
...
> negative, because removing the hashes has its "cost" too). W.A.
> mentioned that the total number of hashes loaded was 2 million, so
> removing 8 thousand would really not make a difference.
Good point - it's still a variable, but not likely as significant as
I'd initially thought it would be.
>> Please be aware that the MPI patch by itself induces (as I recall)
>> 10-15% overhead in a single-core run.
>
> Huh? For "incremental" mode, it should have no measurable overhead.
This is what my experimentation showed. Whether it's the MPI
initialization or something else, the difference between patched and
non-patched was statistically significant on my Phenom x4. I'll
repeat the tests to get more precise numbers, but it's why I made sure
it was optional.
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
