The initial replication is 10 and the minimum quorum is 1.

So is it worth continuing when someone has already succeeded in crunching a WU ? Wouldn\'t it be better to cancel and look for another WU ?

For example, in this WU, computer 983943 already has the status \"Success/Done\"

I suppose you got all the information you need. So why should we continue to crunch this WU ?

Thanks for your answer

Welcome to the CPDN message board.

Computers are machines, and identical machines will produce identical results. However, computers differ and the results they produce therefore differ.

Generally speaking, Windows/Intel machines will agree with each other, Windows/AMD machines will agree with Windows/AMD machines and Darwin/Intel with Darwin/Intel. Linux/Intel machines tend not to agree with each other, Linux/AMD agree more. Careless overclocking will reduce agreement too.

So, different BOINC hosts will only agree if the operating system and processing chip are the same.

It has been shown by statistical analysis of the results that the variations between different machines have the same properties as variations in initial conditions (see here, Knight et al.). So, a WU that produces a variety of results is perfectably reasonable from a physical point of view.

I can\'t personally see the point of having more than two complete duplicates of any model. But you won\'t know whether the results are actually the same until the model has finished, so you might as well finish it...

(Your computers are hidden, so it\'s not possible to see whether your model duplicates, or is likely to duplicate, any other.)

I made my computers visible for you to check.

In the above example, the successful machine is :
CPU type : GenuineIntel Intel(R) Core(TM)2 Duo CPU E8400 @ 3.00GHz [Family 6 Model 23 Stepping 10]
OS : Linux 2.6.27.29-0.1-pae

As mine is :
CPU type : GenuineIntel Intel(R) Core(TM)2 Quad CPU Q8200 @ 2.33GHz [Intel64 Family 6 Model 23 Stepping 7]
OS : Microsoft Windows 7 Home Premium x64 Edition, (06.01.7600.00)

If I have understood your answer, with the same type of CPU, it wouldn\'t have been useful to continue but, as we have different OS, I\'d better keep on crunching this WU.

My purpose is not to gain as many points as possible but to be more efficient for the search by avoiding exact duplicates.

Regards.

... as we have different OS, I\'d better keep on crunching this WU.

That\'s right. Since the completed model is Intel/Linux and they don\'t agree even with apparently similar computers, my advice would have been to continue even if you had a Linux/Intel computer.

A few duplicates could be useful to the project as it would help exclude unstable machines - but only a few. Since CPDN models are long relative to other BOINC projects, CPDN doesn\'t use the WU parameters very intelligently (quorum etc.); it would be easier for us if they did, but I suspect that would simply make their experiments longer and longer (i.e. the time taken to get a useful ensemble of individual models).

Then, according to your answer, I will keep an eye and sometimes cancel one of my WUs but mainly keep on crunching.

Thanks for your very specific answers.