[CoLoCo] How do I make a program fully utilize my dual-core processor?

Ringo 2600denver at gmail.com
Wed Oct 7 00:04:48 BST 2009

Hash: SHA1

There's an awesome platform for this called BOINC which is run out of
berkeley. You sign up for "projects" who give you "work units" and then
your computer works on it while idle or whenever you set. It works on
Ubuntu and IIRC it's in the repos. It's got a nice GUI for people who
dig that as well. Seti at Home, cancer research, cryptography research,
protien folding, etc. all have boinc projects.


Andrew Barney wrote:
> Does the term "distributed workload" refer to multiple computers working in
> unison on the same task?
> Because i would think that if trying to crack passwords that multiple
> systems (perhaps a computer lab) would be the way to go.
> If that's what it means then, i would like to know of any programs that use
> distributed workloads other than cracking software. And even some info on
> how people program code to do that. Is it some sort of P2P software?
> I know awhile back there were some researchers using peoples screensavers to
> do cancer research...
> -Andrew
> On Mon, Oct 5, 2009 at 8:14 PM, Neal McBurnett <neal at bcn.boulder.co.us>wrote:
>> http://pdfcrack.sourceforge.net/faq.html says it can be done:
>> ----
>> Does PDFCrack support distributed and/or multicore/multicpu-systems?
>> Not yet. The project is open for contributions! ;)
>> Distributed workloads can be done by some clever working with the
>> save-files though but I have not tried it.
>> ----
>> I don't know what it means about save-files, but I suggest looking into it.
>> Neal McBurnett                 http://neal.mcburnett.org/
>> On Mon, Oct 05, 2009 at 08:30:35PM -0400, Ringo wrote:
> I'm actually using pdfcrack, so I'm not technically breaking a hash.
> Unfortunately, it only seems to do one thread at a time. I suppose I
> could have one instance working on an x character password and one
> instance working on an x+1 character password but that would require
> some monitoring.
> It's the only pdf cracking utlility I've found but if people know of
> others I'd be thrilled to try them.
> Ringo
> Ryan Maki wrote:
>>>>> Additionally, serious password cracking software might also be able to
>>>>> utilize your graphics card, depending on make and model.~Ryan
>>>>> On Mon, Oct 5, 2009 at 4:30 PM, Neal McBurnett <neal at bcn.boulder.co.us
> wrote:
>>>>>> I'd be surprised if good cracking applications didn't already have an
>>>>>> option to do multi-threading to use all your cores.  What software are
>>>>>> you using?
>>>>>> -Neal
>>>>>> On Sat, Oct 03, 2009 at 06:51:37PM -0400, Ringo wrote:
>>>>> Thanks for all of the great responses! Looks like for now I'll be
>>>>> sticking to just one core for cracking. Recovering this password
>>>>> unfortunately isn't enough of a justification for me to go in and hack
>>>>> the source.
>>>>> Ringo
>>>>> NICK VERBECK wrote:
>>>>>>>>> If you wrote the program yourself or have access to the source. You
>>>>>>>>> could extend it to use Threads. However with threads you can truly
>>>>>>>>> only fire-up as many threads as you have cores. Each thread will
>>> use a
>>>>>>>>> separate core to run in, but once you get 2 threads in the same
>>> core
>>>>>>>>> you will start context switching between each thread in that core
>>>>>>>>> slowing down the actual speed of those 2 threads.
>>>>>>>>> On Sat, Oct 3, 2009 at 8:31 AM, Neal McBurnett <
>>> neal at bcn.boulder.co.us>
>>>>>>> wrote:
>>>>>>>>>> In general, the problem you identify is one of the most daunting
>>>>>>>>>> issues facing computer science.  It is getting much harder to
>>> speed up
>>>>>>>>>> individual processors, so the way to give people more power is to
>>> give
>>>>>>>>>> them more cores.  But we often can't find a suitable way to take
>>>>>>>>>> advantage of them to solve a given problem....
>>>>>>>>>>  http://en.wikipedia.org/wiki/Parallel_computing
>>>>>>>>>> It all depends on exactly what you want to do.  You are in luck
>>>>>>>>>> because recovering a password is easily done in parallel, as James
>>>>>>>>>> notes.  But many other interesting tasks can't be easily
>>> parallelized.
>>>>>>>>>> Neal McBurnett                 http://neal.mcburnett.org/
>>>>>>>>>> On Sat, Oct 03, 2009 at 07:35:00AM -0600, James Wyatt wrote:
>>>>>>>>>>> Assuming both instances can work on different hashes you could
>>> run
>>>>>>> your
>>>>>>>>>>> app twice and assign processor affinity to each process.
>>>>>>>>>>> http://www.linuxjournal.com/article/6799
>>>>>>>>>>> You could do something with erlang if you wanted to do it with
>>> style,
>>>>>>>>>>> but that would certainly be overkill.
>>>>>>>>>>> Jim
>>>>>>>>>>> On Sat, Oct 3, 2009 at 1:31 AM, Ringo <2600denver at gmail.com>
>>> wrote:
>>>>>>>>> Hey Ubuntu experts,
>>>>>>>>> I've got an intel dual-core processor which Ubuntu (intrepid) runs
>>>>>>> great
>>>>>>>>> on. It will fully utilize both cores if I've got lots of programs
>>>>>>>>> running but each program is confined to only one core.
>>>>>>>>> I've looked around online to find out how to make a program use
>>> both
>>>>>>>>> cores, but I can't find any advice on this outside of the
>>> convoluted
>>>>>>>>> process of running a program inside a virtual machine. I'm trying
>>> to
>>>>>>>>> recover a password from a hash and one core is at 100% while the
>>> other
>>>>>>>>> is around 3% usage.
>>>>>>>>> Any ideas?
>>>>>>>>> Thanks,
>>>>>>>>> Ringo
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