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Posts by Ingleside

1) Questions and Answers : Wish list : Using GPUs for number crunching (Message 48739)
Posted 11 days ago by Ingleside
Assuming no major problems with the compiler the next step is professional development of your programming staff with training on GPUs. At this point you might be in a position to know if GPU processing is a reasonable option.

Well, AFAIK all currently active climate-models uses SSE2-optimizations, and my guess this means they're using double-precision. Since the fortran-compiler linked a few posts back is CUDA, and Nvidia-cards has abyssimally poor double-precision-speed of only 1/24 single-precision-performance, except if you pays $$$$ for the professional cards, even a top-end Nvidia-GTX780Ti only manages 210 GFLOPS at most. A quad-core (8 with HT) cpu on the other hand is around 100 GFLOPS. Meaning even best-case the Nvidia-GPU will only be 2x faster than CPU. In reality even 50% performance on GPU can be too high, meaning your "slow" CPU is outperforming your "fast" GPU.

So, unless can use single-precision on most of the calculations, a CUDA-version of CPDN is a waste of development-time.

Instead of CUDA, an OpenCL-compiler would be more interesting, since OpenCL also works with the much faster Amd-GPU's. But even with this additional speed, it's still unlikely can get a climate-model to run faster on GPU than CPU.
2) Message boards : Number crunching : No Tasks Available (Message 48299)
Posted 44 days ago by Ingleside
There was a nasty bug in v7.2.39 which could be causing the download errors.

Haven't been keeping-up with client-changes recently so wasn't aware of this.

v7.2.42 is a bug-fix - maybe the ones you're seeing with download errors and v7.2.42 have upgraded the client in the meantime? Can you check whether the individual failed tasks were attempted under v7.2.39, whatever client they're running now?

Did only find one of my wu's having someone reporting as v7.2.42 with download-error, it's host 1289490 and a quick look reveals 7 errors at the same time. Interestingly enough they're reported as "error" and not "download error". Also, it's only 6 minutes between being assigned and reported as error, so clearly someone manually hitting "update". While it's possible they did swap BOINC-client during these 6 minutes before reporting the errors, this info isn't available anywhere so...
3) Message boards : Number crunching : No Tasks Available (Message 48285)
Posted 45 days ago by Ingleside
The permanent http error is only happening to a few people, so is most likely a problem with their computer.

Well, taking a look on the wu's I've downloaded, while I've not had any download-errors myself the current results are:
90 wu's downloaded, of these:
38 error-free (atleast for now).
39 wu's with download-errors.
21 wu's with computing-errors.
48 total download-errors.
27 total computing-errors.
3 wu's errored-out due to too many errors.

43% of the wu's having download-errors is in my opinion too high, so even if only a "few" users has problems they're managing to generate lots of errors. Since atleast some of these users seems to have no problems crunching other BOINC-projects, it's a little strange if where's a problem with their computers.

Now I've not checked every download-error, but atleast the checked on was from users running BOINC-version 7.2.39 or 7.2.42. If this indicates either a problem with current BOINC-clients or CPDN's server-setup I've no idea about, it can also just be all errors didn't check is from different BOINC-versions.

BTW, appart for all the download-errors, 23% of wu's generating atleast one computing-errors seems on the high side to me.
4) Message boards : climateprediction.net Science : New project launch tomorrow: Weather@home 2014: the causes of the UK winter floods (Message 48270)
Posted 46 days ago by Ingleside
Welcome to the forums. :)

edit - seems the homepage now has been fixed.
5) Message boards : Number crunching : No Tasks Available (Message 48269)
Posted 46 days ago by Ingleside
Not aware of any download-errors, but had 4 models crashing-out with the following message:
<stderr_txt>

Model crashed: INITTIME: Atmosphere basis time mismatch tmp/xaakm.pipe_dummy 2048
Leaving CPDN_Main::Monitor...
Called boinc_finish

</stderr_txt>

The wu's are 8683247, 8683249, 8683250 and 8683251.

On the same computer some of the other models had already been running for a few hours, and another model started successfully a few seconds after the 4 crashing ones. No idea if any other problems, since no way to know how many of the models has started crunching (no access from here).
6) Message boards : Number crunching : Microsoft Visual C++ Runtime Error (Message 48267)
Posted 46 days ago by Ingleside
It's a problem that's been cropping up for a couple years, and no definitive answer or cure has been found in all of that time.
All that can be done is to offer sympathies, and hopes that the next one will work OK.

Atleast my experience (under windows) is if you installs BOINC as a service it means the popup-message can't be shown, so the model will just silently crash-out on it's own.

The disadvantage is you can't install BOINC as a service if you're also doing GPU-crunching.

So for anyone not doing GPU-crunching, installing as a service won't fix some CPDN-models crapping-out, but it should atleast happen without the spamming popup-messages.



7) Message boards : Number crunching : VANISHING WU'S (Message 48061)
Posted 81 days ago by Ingleside
Every night at midnight your time you'll still have your work quota put back to one model per core per day.

Uhm, in older BOINC server-code it was midnight server-time, not user-time, so for CPDN this would equal midnight GMT in the winter.

Since having all quota-limited computers connecting the hour after midnight server-time gave an extra spike in server-load, in more resent server-code the "midnight" is instead randomly assigned to individual computers, meaning someone with multiple computers can have one computer getting a new quota at 01:23:45, another at 12:33:44, a third at 05:43:21 and so on. I'm not sure if CPDN has resent-enough code to have this functionality or the older midnight-server-time-code...



8) Message boards : Number crunching : Reporting - Errors while computing - (Message 47632)
Posted 148 days ago by Ingleside
"Computing allowed"
1] while computer is in use
2] while processor usage is less than 0 percent

I'll change "Only after computer has been idle for" to 0 minutes, it was on 3.00mins.
{not entirely sure what this latter setting actually means or really remember why it was on 3.00}

You're not allowed to set "has been idle for" to zero minutes, even as has already been mentioned this setting isn't used if you don't suspend computing for any reason. While it's possible to manually edit the preference-file (either override or general) and set it to zero, if you do this the client-default is used instead, and this probably is 3 minutes.

Some other settings on the other hand does accept zero minutes, and also a little inconsistently zero percent as far as processor-usage means 100%.
9) Questions and Answers : Windows : C++ error continually occurs (Message 47581)
Posted 155 days ago by Ingleside
So was there any definitive fix for this problem? I've got it too.

In my experience running BOINC as a service will "fix" the problem, atleast as far as a dialogue popping-up and a cpu-core sits idle until you click on the message goes. Models can still crash with C++ error, and it's also possible a crash will just leave model running even after hitting 100%, but atleast you'll not get the popup-message any longer.

If you're also using your GPU for crunching on other projects, service-installation will unfortunately not be an option.
10) Questions and Answers : Windows : Windows 8.1, a caution... (Message 47409)
Posted 175 days ago by Ingleside
I found it impossible to install boinc in its own partition, as I've done since CPDN merged with boinc. Installation was also impossible as a 'service' unless all three options were accepted, including 'screensaver.'

Atleast this part of your problems is you're insisting on trying to run an ancient BOINC-client what never has been and never will be supported by Windows 8.x.

Windows 8.0 and MacOS "Mountain Lion" or later OS-Versions demands BOINC v7.0.xx or later BOINC-versions to work correctly.


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