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benscott

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Message 76938 - Posted: 21 Feb 2024, 21:06:46 UTC

A problem I have seen for a long time is the GFLOPS number for each work unit. The more GFLOPS the faster the unit runs!
For example:
4079 GFLOPS about 3 hours 30 minutes run time.
65284 GFLOPS about 20 minutes run time.

A side effect of this is that when one of those 65284 GFLOP work units is downloaded BOINC thinks it will take a full day to run and doesn't download anything else until it finishes.
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Profile Keith Myers
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Message 76939 - Posted: 22 Feb 2024, 0:42:47 UTC - in response to Message 76938.  
Last modified: 22 Feb 2024, 0:58:12 UTC

A problem I have seen for a long time is the GFLOPS number for each work unit. The more GFLOPS the faster the unit runs!
For example:
4079 GFLOPS about 3 hours 30 minutes run time.
65284 GFLOPS about 20 minutes run time.

A side effect of this is that when one of those 65284 GFLOP work units is downloaded BOINC thinks it will take a full day to run and doesn't download anything else until it finishes.

You are correct. I've got one of each type running. The estimated GFLOPS/sec is the same for both tasks at 0.92 GFLOPS/sec.
But the 4079 GFLOPS task is going to run for 1 hour 50 minutes and the 65,284 GFLOPS task is only estimated to run 22 minutes.

[Edit] I pinged Kevin to this thread for his attention.
[Edit2] This is backwards from standard BOINC client convention that the task property of estimated GFLOPs reflects the total amount of computation power needed to crunch the task.

Disregarding BOINC's broken ability to properly calculate GFLOPS for gpus, it should get this correct for cpu computation power based on the benchmark profile capability of each host.
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Profile Bill F
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Message 76940 - Posted: 24 Feb 2024, 10:23:30 UTC

I had not been able to put my finger on what I was seeing different in my downloads. My four PC's as they are downloading work ... but yes it is in smaller amounts Hopefully this will be the answer and it can easily be corrected.
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Profile Kevin Roux
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Message 76941 - Posted: 26 Feb 2024, 7:53:48 UTC

I will put it on the list of things to look at this week.
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Profile Keith Myers
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Message 76942 - Posted: 27 Feb 2024, 1:42:54 UTC - in response to Message 76941.  

Thanks Kevin, appreciated.
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Profile Bill F
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Message 77224 - Posted: 5 Sep 2024, 20:05:18 UTC

Once the GFLOPS issue is resolved Volunteers that process multiple projects on a system may see an increase in the number of MW tasks that download when their system does a MW task request.

Perhaps after the current application rework and testing is complete Kevin will be able to work this issue into his schedule.

Bill F
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Profile Bill F
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Message 77241 - Posted: 29 Sep 2024, 19:28:31 UTC

Kevin

Have you been able to set aside any time to re-visit the GFLOPS calculation issue for the project ?

Thanks
Bill F
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Profile Keith Myers
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Message 77247 - Posted: 30 Oct 2024, 18:43:09 UTC - in response to Message 77241.  

+1
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Tuba Jim

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Message 77248 - Posted: 31 Oct 2024, 3:18:15 UTC - in response to Message 76940.  

and us slow guys get them done in two days or so..Kinda comes in groups that lasts for a couple weeks or so then gets back to normal for a week or so. My average looks like a curved sawtooth. Well, it doesn't cost me anything I suppose.
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Profile Bill F
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Message 77264 - Posted: 5 Nov 2024, 4:48:37 UTC - in response to Message 77248.  

Well if the Project did a better job of estimating the CPU power of each Client system. And did a better job of estimating how many Tasks to give each client system ... (GFLOPS Fixed ...)
Then some of the saw tooth might not be so extreme.
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alanb1951

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Message 77266 - Posted: 5 Nov 2024, 13:22:55 UTC

Just a thought -- isn't the problem with the GFLOPS estimate that it is based in some way on the number of "particles" in the data being analyzed but it doesn't (or cannot) take account of where they are relative to the main area of computational focus? (I may be phrasing that badly...)

If the vast majority of a calculation involves "empty space" it probably runs a lot quicker. If it takes a lot of effort at workunit generation time to decide whether that might happen, that could be a problem :-) -- however, the consistency of the inverse relationship between GFLOPS estimates and actual run time suggests that a simpler fix would actually cover most cases...

Cheers - Al.
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Message 77270 - Posted: 5 Nov 2024, 20:05:57 UTC - in response to Message 77266.  

Nope ... I think that you might be thinking of a different Science Estimate not GFLOPS which is not science related in anyway.

GFLOPS is a calculation that the BOINC Project (MilkyWay@home) makes regarding the processing power of each Client system's power.

Is it an old slow system with few cores or ... is it a new powerful system with lots of cores and speed ? The calculated estimate is used by the Project to send more work to a power system and less to the older slower old systems. The thought is that more work for those who can handle it and less to those who might struggle to complete by the task deadline.

Bill F
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alanb1951

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Message 77272 - Posted: 7 Nov 2024, 1:58:24 UTC - in response to Message 77270.  
Last modified: 7 Nov 2024, 2:04:11 UTC

BillF,

You are quite right; I was thinking of the "Estimated computation size" (which it cites in GFLOPs [note the small 's'] when it reports it in the BOINC Manager's task properties. I should've either called it something else or got the capitalization right :-) -- I'll plead that I paid more attention to the thread title than I should have done.

I seem to recall (possibly a couple of "admins" ago) that it was explained that the likely computation size was based on a [simplistic] knowledge of where in the complete data stream the WU was targetting and the nature of the stream at that point. Hence my [poorly labelled] observations.

Cheers - Al.
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Message boards : Number crunching : GFLOPS backwards

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