Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Sun, 15 Apr 2012 09:16:24 +0530
From: SAYANTAN DATTA <std2048@...il.com>
To: john-dev@...ts.openwall.com
Subject: Re: MSCash2 OpenCL (was: OpenCL tests on HD 7970)

Hi,

On Sun, Apr 15, 2012 at 7:00 AM, Solar Designer <solar@...nwall.com> wrote:

> It became a lot slower:
>
> user@...l:~/john/magnum-jumbo/src$ ../run/john -te -fo=mscash2-opencl
> -pla=1
> OpenCL platform 1: AMD Accelerated Parallel Processing, 2 device(s).
> Using device 0: Tahiti
> Benchmarking: MSCASH2-OPENCL [PBKDF2_HMAC_SHA1]... DONE
> Raw:    36781 c/s real, 52459 c/s virtual
>
> GPU load is now reported at 94%.  Probably it's not such a good
> indicator, then.  I am also able to get it to 99% by simultaneously
> running two instances of JtR using the 7970, but the cumulative speed
> does not improve much (46k c/s above, 60k c/s with your previous code
> version - still slower than the 75k c/s with one instance of the
> previous version).
>

The results are unexpected and I think it would require some local work
size optimization and some local memory optimizations.  However my the new
codes perform better on Cayman(6970) as reported by Samuele.  It achieved
around 37% improvement over the previous version.Details are given below.
 I think this is the reason why hashcat keeps so many versions of kernel
code each for different gpu.   It seems like cayman, cypress and RV770 have
more or less similar architecture. However since GCN is a radical
 departure from previous generation architectures it is better to have
a separate kernel for GCN .  Comparing to hashcat it achieved 309k c/s on
dual 6990.  Therefore 54k c/s is on 6970 is closer to their results.
 However  once I get my hands on GCN I will write a fully optimized kernel
for it but for now the decision is upto you.

i did some test, on my 6970 this is the speed of the previous version:
>


> ../run/john -test -fo=mscash2-opencl
> OpenCL platform 0: AMD Accelerated Parallel Processing, 2 device(s).
> Using device 0: Cayman
> Benchmarking: MSCASH2-OPENCL [PBKDF2_HMAC_SHA1]... DONE
> Raw:    39384 c/s real, 400000 c/s virtual
>
> this of the one you gave me
>


> ../run/john -test -fo=mscash2-opencl
> OpenCL platform 0: AMD Accelerated Parallel Processing, 2 device(s).
> Using device 0: Cayman
> Benchmarking: MSCASH2-OPENCL [PBKDF2_HMAC_SHA1]... DONE
> Raw:    54008 c/s real, 412903 c/s virtual

[ CONTENT OF TYPE text/html SKIPPED ]

Powered by blists - more mailing lists

Your e-mail address:

Powered by Openwall GNU/*/Linux - Powered by OpenVZ