Bernd: Solution to the cross-platform issue?

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Martin P.
Martin P.
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7 Jul 2007 20:16:58 UTC
Topic 192941
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    I currently lose appr. 20-25% of all completed work-units to the famous cross-platform validation issue. e.g. http://einsteinathome.org/workunit/34110776 and http://einsteinathome.org/workunit/34073730 .
    Although these invalid work-units get deleted very quickly and therefore it is very complicated to monitor them I manually logged them for a week now and see appr. every 4th work-unit being INVALID although claimed credit is exactly the same as the others. Also my RAC went down from over 1,000 to 739 nowadays using the exact same machines and schedule as before. Seems to be mainly an issue between MacOS X and most flavours of Windows.

    We heard for months that a new version for MacOS X is just about to be released but nothing happened so far. Please give us a timeline when we can expect a compatible version.

    Ziran
    Ziran
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    Bernd: Solution to the cross-platform issue?

    7 Jul 2007 20:39:21 UTC
    Message 69554
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      6 Jul 2007

      Quote:

      Just to keep you updated of our plans, mainly regarding the cross-platform differences:
      - Early next week (probably Monday) we'll issue a new validator that should make things easier for transition and probably fix some invalid results by itself
      - After the new validator is in place, we'll issue a new set of Apps for public Beta Test (for all platforms) that incorporate the fixes accomplished so far. I'll keep on tracking problems and fixing bugs I find until the very last moment. The new Apps will also incorporate a new feature that we might need.
      - If it turns out that we need this feature (using pre-calculated files instead of doing the calculations in the Apps to avoid platform differences there), we will issue new workunits (actually a new workunit generator) that will make use of this feature after the new Apps have been made "official".
      - Once we got the validation working properly, I'll work on speeding up the computation in the Apps. The current code I plan to use for parts of the calculation btw. doesn't make use of neither modf() nor ftol() anymore but actually uses bit-operations to achieve something similar.

      BM

      http://einsteinathome.org/node/192905&nowrap=true#71592

      Then you're really interested in a subject, there is no way to avoid it. You have to read the Manual.

      Martin P.
      Martin P.
      Joined: 17 Feb 05
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      RE: 6 Jul 2007RE: Just to

      7 Jul 2007 21:59:23 UTC
      Message 69555 in response to message 69554
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        Quote:
        6 Jul 2007
        Quote:

        Just to keep you updated of our plans, mainly regarding the cross-platform differences:
        - Early next week (probably Monday) we'll issue a new validator that should make things easier for transition and probably fix some invalid results by itself
        - After the new validator is in place, we'll issue a new set of Apps for public Beta Test (for all platforms) that incorporate the fixes accomplished so far. I'll keep on tracking problems and fixing bugs I find until the very last moment. The new Apps will also incorporate a new feature that we might need.
        - If it turns out that we need this feature (using pre-calculated files instead of doing the calculations in the Apps to avoid platform differences there), we will issue new workunits (actually a new workunit generator) that will make use of this feature after the new Apps have been made "official".
        - Once we got the validation working properly, I'll work on speeding up the computation in the Apps. The current code I plan to use for parts of the calculation btw. doesn't make use of neither modf() nor ftol() anymore but actually uses bit-operations to achieve something similar.

        BM

        http://einsteinathome.org/node/192905&nowrap=true#71592

        Thanks Ziran,

        the title of that thread "Windows Beta Test App 4.24 available" did not seem to be appropriate with my MacOS X problem.

        Martin P.
        Martin P.
        Joined: 17 Feb 05
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        Until they sort out the

        9 Jul 2007 10:37:07 UTC
        Message 69556
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          Until they sort out the problem and an optimized version for PPC is released I'll reduce the share for E@H from 60% to 10%. Let's wait and see...

          Bikeman (Heinz-Bernd Eggenstein)
          Bikeman (Heinz-...
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          RE: Until they sort out the

          9 Jul 2007 11:51:16 UTC
          Message 69557 in response to message 69556
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            Quote:
            Until they sort out the problem and an optimized version for PPC is released I'll reduce the share for E@H from 60% to 10%. Let's wait and see...

            The cross-validation problems are possibly fixed this very week.

            I guess we are both crunching for CPDN? Do they have at least plans for platform-optimized apps? I haven't followed discussions at CPDN for a long time.

            CU

            BRM

            Martin P.
            Martin P.
            Joined: 17 Feb 05
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            RE: RE: Until they sort

            9 Jul 2007 13:12:31 UTC
            Message 69558 in response to message 69557
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              Quote:
              Quote:
              Until they sort out the problem and an optimized version for PPC is released I'll reduce the share for E@H from 60% to 10%. Let's wait and see...

              The cross-validation problems are possibly fixed this very week.

              I guess we are both crunching for CPDN? Do they have at least plans for platform-optimized apps? I haven't followed discussions at CPDN for a long time.

              CU

              BRM

              There is no CPDN-client for MacOS X anymore, they quit support. However, there is an excellent, optimized client for SETI@Home!

              Bikeman (Heinz-Bernd Eggenstein)
              Bikeman (Heinz-...
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              RE: RE: RE: Until they

              9 Jul 2007 13:35:35 UTC
              Message 69559 in response to message 69558
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                )

                Quote:
                Quote:
                Quote:
                Until they sort out the problem and an optimized version for PPC is released I'll reduce the share for E@H from 60% to 10%. Let's wait and see...

                The cross-validation problems are possibly fixed this very week.

                I guess we are both crunching for CPDN? Do they have at least plans for platform-optimized apps? I haven't followed discussions at CPDN for a long time.

                CU

                BRM

                There is no CPDN-client for MacOS X anymore, they quit support. However, there is an excellent, optimized client for SETI@Home!

                There is one for Intel MacOS X (I'm using that one), so I guess they abandoned the Power PC platform?

                The SETI@Home optimized clients are cool, but I left S@H because I fail to see any science being done with the tons of data they collect.

                Upps, getting off-topic, I guess. Sorry

                CU

                BRM

                Luis
                Luis
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                I just remember somebody else

                9 Jul 2007 20:38:37 UTC
                Message 69560
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                  I just remember somebody else that had cross platform issues with linux before:extended precision Turns out in Linux x86 the math unit is always set to extended precision mode (80 bits) while most other platforms use double precision (64 bits). That is mostly irrelevant unless you have code like 'if (10*0.3==3)' in which case minute differences in the least significant digits show up as different integer results.

                  tullio
                  tullio
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                  I found this tutorial useful

                  10 Jul 2007 4:38:10 UTC
                  Message 69561
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                    I found this tutorial useful for understanding floating point arithmetics:
                    CERN Computing Seminar
                    Tullio
                    Go to Archives, January 2005, Computing with floating point: it's not dark magic, it's science

                    Bikeman (Heinz-Bernd Eggenstein)
                    Bikeman (Heinz-...
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                    Interesting stuff indeed,

                    10 Jul 2007 9:49:47 UTC
                    Message 69562
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                      Interesting stuff indeed, thanks for posting the links.

                      BTW, just saw this in the news section of the E@H homepage:

                      Quote:

                      July 10, 2007
                      We have started a new validator. This change is one of the steps needed to get rid of the cross-platform validation problems.

                      CU

                      BRM

                      Martin P.
                      Martin P.
                      Joined: 17 Feb 05
                      Posts: 162
                      Credit: 40156217
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                      RE: Interesting stuff

                      17 Jul 2007 9:03:13 UTC
                      Message 69563 in response to message 69562
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                        Quote:

                        Interesting stuff indeed, thanks for posting the links.

                        BTW, just saw this in the news section of the E@H homepage:

                        Quote:

                        July 10, 2007
                        We have started a new validator. This change is one of the steps needed to get rid of the cross-platform validation problems.

                        CU

                        BRM

                        Does it - finally - work?

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