Each time it tries to load a 6 Mb file
27 Jul 2005 3:10:52 UTC
Topic 189612
(moderation:
You guys there said that a new 6 Mb file will be downloaded once after since you have changed to a new S4 run. But I see that my client downloads this huge file for about fourth times along with 5 or so WU's than it crunches them, uploads, gets credits and downloads similar huge file again.
What's wrong? Does anybody know?
Each time it tries to load a 6 Mb file
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Is it downloading the SAME 6MB file each time (l1_XXXX.X) or a different one?
Director, Einstein@Home
RE: Is it downloading the
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It is downloading then new file each time, but this doesn't matter because you guys promised that it will be downloaded only once. But know I'm sitting without work just because I aborted the download 'till I find the reason. So, what should I do?
RE: It is downloading then
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They promised no such thing.
A quote from the FAQ:
The downloads of the Workunits are quite large / too large for modem users.
The Einstein@Home workunits require a large data file (slightly more than 12 MB in size). With a 57.6kb modem, this file will take close to an hour to download. Once you have downloaded it, the Einstein@Home scheduler should send you a number of workunits for that file, so you won't need to download another file for some time. (emphasis mine) However be warned that sometimes the OUTPUT files from Einstein@Home can be quite large, and so it may take an hour or more to upload the results back to the Einstein@Home server.
The bottom line is that if you need to pay an hourly rate for dial up modem service, Einstein@Home is probably not a good thing to run on your computer. Users with broadband internet connections such as DSL (Digital Subscriber Line) and cable modems shouldn't find that these uploads/downloads take more than a minute or so.
I think you have just been unfortunate enough to keep getting WUs that require the large input files. This happens to me sometimes as well, which can be annoying as I'm on dial up. But most of the time, the input files are re-used.
RE: RE: Is it
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On average a single input file (6+ Mb) will be used for around 6 WU. In a survey around Easter the max was in the teens, if I remember rightly.
If you are unlucky you can get a run of several WU where each WU needs a new file -- this only happens when the scheduler is getting rid of the last remnants of old groups of WU, so tends to come round rarely but when it does happen it happens to quite a few people at once.
I think you misunderstood the 'promise'. It wasn't quite a promise anyway, but what was said is that a given file will only be downloaded once. This is true, it is downloaded only once. Then, for as long as E@h has any work connected to that file, when your client goes back for more work you will get given work from that file again. After all the work on that file has been done, you get a new file.
What you need to do is decide if you are willing to do so much downloading. If so, allow it to resume downloading its files. What you have seen is going to be pretty typical of how it will go on, within this project.
If that is not OK for you, then swap to another project: nobody here will be offended (indeed the scientists will be grateful for the work you did already).
Either LHC or Predictor will be more modem friendly for example, and once work comes online Orbit will be ideal for modem users.
Climate Predictipn has huge uploads, but several months between them as a CPDN wu takes from six weeks to six months to crunch, dpending on machine speed, other projects, etc. And you can timetable the uploads to happen at a weekend if that suits your dialup rates, as the deadline there is about 11 months.
These file sizes are not Einstein being bloody minded, as some people seem to think. Rather they are an inherent part of the physics of this project. Other projects have different technical needs.
~~gravywavy
http://boinc-doc.net/boinc-wi
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http://boinc-doc.net/boinc-wiki/index.php?title=Einstein%40Home_FAQ
That page in the wiki has some data on how many workunits per data file. Of course it still varies per file and with the turnaround time on the computer.
BOINC WIKI
BOINCing since 2002/12/8
RE: I think you
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Or you can read the 'official' explanation regarding downloading the input file from the FAQ, as I quoted earlier in this thread. ;)