hi people

i have just joined cpdn coming over from seti

im sure it has been covered before but ; is there an optimised app available ? what sort of optimisation is in the stock app ?

also im running intel mac which appears to be an older version number to the rest the platforms, will this make a difference regarding credit rewarded ?

what is the best platform for cpdn as far everyones experience is concerned ?

regards

adream

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Hi Dreamer, welcome to the forum.

As far as I know, all the current model versions including Mac have improved (ie reduced) I/O - input-ouput - usage and should therefore put less strain on memory. We all get sent the same standard version, though of course depending on Windows/Linux/Mac. Within each of these three, we can\'t choose which version we get. It\'s always the most up-to-date version from Oxford.

The \'platform\' is really boinc in all cases, so I assume you are wondering whether Windows or Linux or Mac is best for cpdn. At one time the Linux models ran slightly more slowly than the others, but I\'m not sure whether this is still the case. Basically in cpdn, because the models take so long to complete, the significant factor is how likely it is that you\'ll get the model to completion. From this point of view, I don\'t think it matters at all whether you use Windows, Linux or Mac.

We don\'t get complaints about any of the three being more or less generous in the awarding of credits. The credits always depend on the amount of model time (not CPU time) the computer has crunched and trickled up to Oxford, which seems fair.

The best info for new (and old!) cpdn members is in the project READMEs which can be reached through my sig link. Don\'t even think about reading them all, but look at the one about avoiding model crashes. Item #5 there by Mike is really useful, plus item #1 by Les - his easy backup method. On Seti you don\'t need to think about backing up the contents of your boinc folder, but on cpdn you need to do this regularly because if your model does crash, the only way to get it back and continue crunching it is by restoring your most recent backup.

On that cpdn independent forum where the READMEs are, everyone can read but you need to register separately to post.

Hope that helps.

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Cpdn news

thanks for the quick and informative reply mo.v

interesting to hear about the problems with completion , i have had one model fail already

the problem with backing up the boinc data folder on mac is that permission issues prevent the folder from copying or being moved which makes life pretty difficult

lets hope my machine which has 8 cores and 7gb of ram is stable enough :-)

thanks again
regards


adream

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8 cores!

In Oxford the programmers seem to have a wide selection of computers running models for testing purposes and at one time the fastest of all was a Mac.

The data that computers send back to the servers in the trickles is useful for the researchers, but obviously the more models that reach the end, the better. So if you could sort out the permissions problem to enable you to make backups, this would be useful.

The completion problem isn\'t because the models are unstable - in fact they\'re very stable indeed, though a few do produce unviable climate and fortunately crash rather than continuing. The problem lies in the sheer length of the workunits. During 4 or 6 months of running a model almost 24/7, all sorts of things can happen.

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Cpdn news

Wow, with 8 cores, I\'d setup BOINC to use 6 of them, let BOINC run always, and leave the other 2 cores for your use exclusively. You can make a significant contribution with a fast machine such as that.

the problem with backing up the boinc data folder on mac is that permission issues prevent the folder from copying or being moved which makes life pretty difficult

It is no problem, when the backup task is running as root, for example with sudo.
I do regulary backups (as root) via tar. For example \"sudo tar -cvpzf backupfile.tar.gz /Library/Application \\Support/BOINC \\Data\". Restore with \"sudo tar -xvpf backupfile.tar.gz\".
In the moment I do this with while BOINC is complete stopped. Btw. Is it OK to suspend the CPDN application and do the backup then ?

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On most platforms you won\'t be able to successfully restore from the backup if Boinc was either suspended or active while it was taken. The reason that even though it isn\'t actively processing, it still has the work files locked, and they won\'t get backed up.

Bit of a pain when you come to restore, and it crashes ... :-(

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I'm a volunteer and my views are my own.
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So if you have automatic backups of the whole system scheduled while the model is running, or when boinc isn\'t exited, once or twice a week you need to make separate backups of the whole boinc folder (after exiting from boinc first). It\'s these separate backups that can be expected to restore successfully and run.

I\'d guess that backups have rescued more models than anything else, ever.

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Cpdn news

...lets hope my machine which has 8 cores and 7gb of ram is stable enough :-)...

adream,

As of today, the top two machines are the same as yours (see here). Note, however, that you may have to configure the machine before it runs properly - have a look at this post, which deals with the shared memory problem.

Iain

PS As to your original question about optimisation, the app is a shed-load of proprietary FORTRAN ported to a PC - there\'s no chance of any version appearing from anywhere but the project team ...