|Subject:||Re: [Help-glpk] Performance decrease with more powerful computer|
|Date:||Tue, 5 Feb 2013 09:14:50 -0500|
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 GallowayOn 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 <address@hidden> wrote:From: Patrik Dufresne <address@hidden>Subject: Re: [Help-glpk] Performance decrease with more powerful computerTo: "Reginald Beardsley" <address@hidden>Cc: "glpk" <address@hidden>Date: Friday, February 1, 2013, 9:49 AMHi Reginald,Here are the hardware specs i'm comparing.System 1Windows XP SP2Intel Core i5 650 @ 3.20GHz 4 MB Cache3GiB DDR3 1066/1333CPU mark (according to cpubenchmark.net) : 3154
Total computation time : 331 secSystem 2Windows XP SP2, Windows 7 64bits, Debian 64bitsCore i7 CPU M 620 @ 2.67GHz 4M Cache4GiB DDR3 1066CPU mark (according to cpubenchmark.net) : 2718
Total computation time : 114 secsSystem 3Windows XP SP2, Debian 64bitsCore 2 Duo CPU E6550 @ 2.33GHz 4 MB Cache L24GiB DDR2 800CPU mark (according to cpubenchmark.net) : 1493
Total computation time : 172 secsI 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 DufresneOn Fri, Feb 1, 2013 at 10:23 AM, Reginald Beardsley <address@hidden> 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 <address@hidden> wrote:From: Patrik Dufresne <address@hidden>Subject: [Help-glpk] Performance decrease with more powerful computerTo: "GLPK help" <address@hidden>Date: Friday, February 1, 2013, 8:56 AMHi,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_______________________________________________Help-glpk mailing list-- http://www.fastmail.fm - A fast, anti-spam email service.
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