[SWLUG] how much more CPU performance can one get these days?

[Mark Summerfield]

On 2009-09-18, Iain Menzies-Runciman wrote:
> Mark,
> 
> Having hit the limits of machines several times in the past you may need
> to change the problem.
> 
> I would assume that you have already done the obvious and optimised the
> code you have (also assuming that you have the source code).

I have the source but it is C and complicated & I can't even think of
changing it. (Also the author is an expert on algorithms for intractable
problems so I doubt I could improve what he's done.)

> From the sounds of it, it is an iterative process, so just running the
> code on many machines at the same time would not help.

That's correct.

> Given that you are on a dual core, I am assuming that you are threading
> and make the most of each core.

I don't know for sure if it is threaded, but if I don't use nice it
manages to use 100% of CPU on my dual core.

> Can the code be parallelised and then split out onto multiple machines
> e.g. using something like PVM or MPI? If it can then you can get
> yourself a small cluster of cheap systems (e.g. 2nd hand systems at £50
> a pop - or if you are like most techies use some of the old systems that
> we have just lying around :-) ) and spread the load out onto a
> distributed cluster. I managed to get a task from 22 hours down to 45
> minutes - but that was PVM spread over 50 machines.

I wish... but there's no way of splitting it up. 

I was really wondering if getting a modern 64-bit quad core would
actually make a significant difference.

Thanks.

> Regards,
> Ming
> ---
> Silicon Blade Consultants
> www.siliconbladeconsultants.com
> 
> On Fri, 2009-09-18 at 08:08 +0100, Mark Summerfield wrote:
> > Hi,
> >
> > Short version:
> >     I have Linux 2.6 2GB RAM Dual Core Pentium D 2.8GHz
> >     What would I need to get 5x the CPU performance?
> >
> >
> > Long version:
> >
> >     I sometimes have to run a program that starts by reading 5-50MB of
> >     data, then spends 12-15 minutes processing (no I/O, no graphics,
> >     pure CPU), then writes out a single 5-100MB output file.
> >
> >     Unfortunately I need to run this program many times to tweak the
> >     input data to get exactly the output I want. So basically, it can
> >     take me a whole day.
> >
> >     I bought my PC a few years ago and was wondering how much
> >     performance had improved in the meantime, and whether I could get a
> >     5x speedup without breaking the piggy bank.
> >
> > Thanks!
> 


-- 
Mark Summerfield, Qtrac Ltd, www.qtrac.eu
    C++, Python, Qt, PyQt - training and consultancy
        "Rapid GUI Programming with Python and Qt" - ISBN 0132354187