Date: Sat, 25 Jul 2009 19:45:51 +0400 From: Solar Designer <solar@...nwall.com> To: john-users@...ts.openwall.com Subject: Re: Average c/s numbers Others have already provided helpful replies (thanks!), yet I think I have something to add. On Thu, Jul 23, 2009 at 07:54:46AM -0400, ISSCP Security wrote: > Can someone tell me what are average c/s numbers? This question is poorly worded, so I'll ignore it. ;-) > Also is there a way to calculate what the c/s numbers "should" be for a specific PC config? For those you obtain with "john --test" (a benchmark), please refer to the wiki page: http://openwall.info/wiki/john/benchmarks > Lastly is there a way to increase the c/s numbers? Yes, there are many ways, including: - use the most optimal make target for your system; - load a larger number of password hashes for cracking at once (you can load multiple files at once); - consider using the --salts=... option in order to take advantage of possible anomalies in the distribution of salts across your hashes; - on a multi-core system, run multiple instances of JtR at once, making them try different candidate password sets or/and attack different sets of salts; - if you're currently building JtR for 32-bit x86, move to x86-64 (CPU, OS, build of JtR) for a slight speedup (typically 10% to 50% for the same CPU, depending primarily on hash type); - use a newer version of gcc (or your CPU, machine, or OS vendor's native C compiler), which might or might not result in a speedup; - tweak the C compiler optimization options, which might or might not result in a speedup; - tweak the code - on your own or/and by using a user-contributed patch; - upgrade your CPU (the rest of the hardware does not matter much). > right now I'm seeing +/- 2924 on a Intel Celeron CPU 2.00 GHz good or bad ? You have provided insufficient information for a "good or bad" type of response. "Intel Celeron CPU 2.00 GHz" (which is not a precise CPU spec, but that's another matter) can't possibly be very fast, though, and I am guessing that you're getting that c/s rate for a FreeBSD-style MD5-based hash, which is "a bit slow" even for a CPU "like that". In general, with questions like this what matters most is the hash type and whether you're getting a given c/s rate on a --test benchmark (then it can be directly compared against results for other CPUs) or when cracking a specific password file (then the "effective" c/s rate is being reported, which depends on the hashes to salts ratio, as well as on a few other things). I could be more specific about this, but for that you need to be more specific first. ;-) I hope this helps - not so much to improve your c/s rate directly, but mostly to improve your understanding of the matter. Alexander -- To unsubscribe, e-mail john-users-unsubscribe@...ts.openwall.com and reply to the automated confirmation request that will be sent to you.
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