Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date: Sat, 5 Jan 2013 10:49:28 +0400
From: Solar Designer <solar@...nwall.com>
To: john-users@...ts.openwall.com
Subject: Re: john and muti-core settings and progress display

On Mon, Dec 31, 2012 at 11:13:02PM +0000, John Hall wrote:
> With single core I saw something like "...trying: Initialguessabc123"
> 
> With multicore I saw something like "...trying Initialguessabc123 - Initialguessxyz456"
> 
> So is john actually running 2 threads and each separately is attempting to discover the hash code?

Perhaps, if you did everything right.  This range output indicates that
JtR is buffering multiple candidate passwords and trying them "at once"
in an attempt to achieve greater speed.

When this happens, there are usually more than 2 of them - in some cases
even thousands.  This may be happening with only one CPU core in use,
too - depending on the algorithm used.

Thus, when you see just one candidate password after "trying: ..." this
implies that only one CPU core is being used by that JtR process,
whereas when you see a range it does not always mean that multiple cores
are being used.

You may want to look at the c/s rate (how it has changed) and CPU load
(e.g., run "top" in another virtual console).

> If so, presume that somehow there is no duplication of effort.

That's correct.

Alexander

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.