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Date: Thu, 24 May 2012 19:58:56 -0300
From: Claudio André <>
Subject: Re: Timing issues

Reading the discussion on john-users, i believe magnum found a bug on 
rounds usage on my code.

I will take a look at it. And i will create a self-test for 4900 rounds 
(it will not impact the final "5000" bech number).


Em 24-05-2012 18:07, magnum escreveu:
> When I tried the high-rounds crypt-SHA512 hash (as seen on john-users)
> on bull just now, I stumbled onto two issues, not really new to me but I
> think they need to be looked at.
> 1. I tested using --max-time=60 but it was not obeyed. This option is
> designed so that if the self-test takes 40 seconds the expected total
> run time would be about 1:40 instead of 60 seconds, but this does not
> explain it (it ran for several minutes before I killed it). I will look
> into this later but I have a feeling it's something with our OS_TIMER=0
> - does that make sense? I have seen other weird things that started to
> happen after we did this change (can't remember exactly what right now,
> I think it was something like "reported time not reflecting wall time").
> 2. When cracking (as opposed to benchmarking) the time before cracking
> actually starts is counted:
> guesses: 0/7680  time: 0:00:00:43  c/s: 175  trying: HC - ��
> guesses: 0/76800  time: 0:00:01:00  c/s: 1279  trying:  W� -  �>
> guesses: 0/176640  time: 0:00:01:23  c/s: 2119  trying: #Z� - #��
> The real speed is constantly at something like 4300 c/s considering it
> did not even start until about 0:40. This makes quick tests like this
> one hard to do (need to run a lot longer, or re-calculate manually which
> is what I did, hopefully not totally wrong). Do we want to change this?
> It could be considered cheating in a way but I think the current
> behaviour is just confusing (say for example you try to follow the
> suggested homing for markov mode - you will end up with a too low level,
> and stop long before your targeted runtime)
> This would of course be mitigated a little by fixing the underlying
> issue that the self-test takes 40 seconds.
> magnum

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