Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Thu, 11 Sep 2014 07:18:54 -0800
From: Royce Williams <>
Subject: Re: nVidia Maxwell support (especially descrypt)?

On Wed, Sep 10, 2014 at 11:54 PM, magnum <> wrote:
> On 2014-09-11 09:02, Royce Williams wrote:
>> Because of the $150 price and relatively low power requirements (~60W,
>> no extra power connector needed) of the new nvidia Maxwell (GTX 750
>> and 750 Ti) cards, and my own interest in descrypt, I'm interested in
>> seeing JtR take advantage of Maxwell if feasible.
> As long as you have OpenCL drivers for it, it's supposed to work and any
> device-specific problems would be a bug (albeit not always "our" bug, I
> recently worked around some really silly bugs in latest AMD drivers).

To clarify for non-programmers like myself: is it up to the drivers,
and not JtR's implementation, to take advantage of the features that
Golubev gushes about?

>From, after a breakdown of
code-specific changes he made:

"Maxwell architecture is simply the best among all GPUs (And, yes,
including AMD ones — because of constant problems with AMD’s buggy
software making fast hardware pointless). At least for
hashing/cryptography purposes."

>> I know that descrypt isn't exactly the hottest topic, but it might be
>> easy to use it as a Maxwell test case.
> BTW I just dropped the DEScrypt-opencl format to the broken/ subdirectory
> because it keeps giving me problems. For example, it fails building under
> later AMD drivers due to excessive use of 'goto'. Some other drivers commit
> suic^Wsegfault while trying to sort it out. I believe using goto in an
> OpenCL kernel is really begging for problems.
> To use it, simply move the files back from src/broken to src, reconfigure
> and re-build. I hope Sayantan will fix it (as well as the memory leak
> discussed before) at some point in time.

Hmm ... I don't see any activity from Sayantan on the mailing lists
since 2012, and his GitHub commits mostly died off a year ago:


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.