The results may consistent:


Core i7 is a quad core processor with HyperThreading, so on Windows XP
it will appear as 8 processors each running at 1.6 Ghz. GLPK can only
use one of these processors so only 12.5% of max.



Core i5 is dual core with HyperThreading. HyperThreading helps Windows'
threading model but does nothing for Linux. You may find that your
Linux has turned it off. So the i5 looks like 2 porcessors each running
at 2.6 Ghz. GLPK can use 50% of this configuration.



You may be able to turn off the HyperThreading on the i7 by changing
your BIOS settings. GLPK will then be able to use 25% of max.



--

Nigel Galloway

[email protected]





On Fri, Feb 1, 2013, at 08:15 AM, Reginald Beardsley wrote:

     Looking at the descriptions I think you're thrashing.  Add more memory
     to system 1, unless of course there's a typo and that should read
     "32GiB" instead of "3GiB"

     --- On Fri, 2/1/13, Patrik Dufresne <[email protected]> wrote:



     From: Patrik Dufresne <[email protected]>

     Subject: Re: [Help-glpk] Performance decrease with more powerful
     computer

     To: "Reginald Beardsley" <[email protected]>

     Cc: "glpk" <[email protected]>

     Date: Friday, February 1, 2013, 9:49 AM



     Hi Reginald,

     Here are the hardware specs i'm comparing.

     System 1
     Windows XP SP2
     Intel Core i5 650 @ 3.20GHz 4 MB Cache3GiB DDR3 1066/1333CPU mark
     (according to [1]cpubenchmark.net) : 3154
     Total computation time : 331 sec

     System 2
     Windows XP SP2, Windows 7 64bits, Debian 64bits
     Core i7 CPU M 620 @ 2.67GHz 4M Cache4GiB DDR3 1066CPU mark (according
     to [2]cpubenchmark.net) : 2718
     Total computation time : 114 secs

     System 3
     Windows XP SP2, Debian 64bits
     Core 2 Duo CPU E6550 @ 2.33GHz 4 MB Cache L24GiB DDR2 800CPU mark
     (according to [3]cpubenchmark.net) : 1493
     Total computation time : 172 secs

     I didn't run the benchmark on the computer it self, but the different
     between the number is big enough to expect better performance from
     System no 1 then System no 3. The total computation time of the problem
     on different platform for the same computer are almost identical. (less
     then 0.5 sec different). It's safe to assume the platform doesn't have
     any impact on the performance.

     I'm using GLPK 4.47 on every platform. On Linux, I did compile it from
     source with default flags. For Windows, I pick the pre-compiled version
     provided by winglpk project.

     To solve the problem, I need to run GLPK multiple time sequentially. I
     may provide dump of every instance of the problem.

     Patrik Dufresne

     On Fri, Feb 1, 2013 at 10:23 AM, Reginald Beardsley
     <[email protected]> wrote:


  Could you  provide a few details?

  System configurations you're comparing?  GLPK version?  Compile time
  options specified?

  There are a huge number of possibilities.  Why do you think the
  computer is "more powerful"?

  Reg



  --- On Fri, 2/1/13, Patrik Dufresne <[email protected]> wrote:



  From: Patrik Dufresne <[email protected]>

  Subject: [Help-glpk] Performance decrease with more powerful computer

  To: "GLPK help" <[email protected]>

  Date: Friday, February 1, 2013, 8:56 AM



  Hi,

  I'm using GLPK in one project and the time taken to compute is longer
  on a more powerful computer. Does it make any sense to you ?

  I don't have any clues about how to debug it. I would really appreciate
  tips to diagnose the problem.

  Patrik Dufresne

  -----Inline Attachment Follows-----



  _______________________________________________

  Help-glpk mailing list

  [4][email protected]

  [5]https://lists.gnu.org/mailman/listinfo/help-glpk



     _______________________________________________

     Help-glpk mailing list

     [email protected]

     [6]https://lists.gnu.org/mailman/listinfo/help-glpk

_______________________________________________

Help-glpk mailing list

[7][email protected]

[8]https://lists.gnu.org/mailman/listinfo/help-glpk

References

1. http://cpubenchmark.net/
2. http://cpubenchmark.net/
3. http://cpubenchmark.net/
4. http://mc/[email protected]
5. https://lists.gnu.org/mailman/listinfo/help-glpk
6. https://lists.gnu.org/mailman/listinfo/help-glpk
7. mailto:[email protected]
8. https://lists.gnu.org/mailman/listinfo/help-glpk

-- 
http://www.fastmail.fm - A fast, anti-spam email service.

_______________________________________________
Help-glpk mailing list
[email protected]
https://lists.gnu.org/mailman/listinfo/help-glpk

Reply via email to