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-   -   Error rates and ECC (https://www.mersenneforum.org/showthread.php?t=28655)

kriesel 2023-06-27 19:02

[QUOTE=S485122;633159]I'm sorry but I drown in your reference information, after two topics and three lines I am lost.[/quote]Well that's unfortunate, regardless of whatever level of exaggeration that might be present. I tried to use bold so someone in a hurry could skim quickly for the observed variations in error rate, then read a bit about any given value, or not. Maybe add some subheadings too?

[quote]if you want to evaluate the error rate of current contributions, you must not look at mismatches which might be a bad or a correct result (often proving a result from previous years bad.) Just look at recent LL results returned. Don't choose a range, don't limit yourself to a few results (as in "quite small sample sizes used"), evaluate the production of a whole year (using "text" for output will provide you with 10000 rows at a time).[/quote]I haven't analyzed it lately yet, but I suspect the current/recent error rate is somewhat a function of exponent. With a given error rate/unit time etc due to cosmic ray interactions or whatever, computations that take longer would have higher probability of error. Averaging together low exponent, medium, high, and very high, or fast, medium, slow and very slow runs, is likely to average together error rates that vary nonlinearly with exponent, & give a value that's inaccurate at either lowest or highest exponent range. On the other hand, statistical sampling error becomes an increasing problem as the available data gets sliced into smaller exponent range, application type, or date range bins. That effect can be estimated.

[quote]But those figures are what we are discussing, i.e. the [b]current[/b] LL error rate and that [b]current[/b] error rate is less than 0,7 %.[/QUOTE]Well, in this thread, I suppose, since you originated it with the first post, about the past year, yes. And I think there are other ways of looking at it that are also useful. Not meaning to hijack the whole thread, and do appreciate the input from others. It's a big part of why I read the forum. The DDR generation being significant I had not thought of.

chalsall 2023-06-27 19:10

[QUOTE=kriesel;633175]Well that's unfortunate, regardless of whatever level of exaggeration that might be present.[/QUOTE]

If I may... Few appreciate the importance of curators.

I have known people who have PhDs who became curators, documenting others' work for future researchers.

It's a thankless job.

Uncwilly 2023-06-27 19:35

[QUOTE=kriesel;633175]I haven't analyzed it lately yet, but I suspect the current/recent error rate is somewhat a function of exponent.[/QUOTE]Also, maybe you have an innate bias because you buy used equipment and run into errors. I have done runs on the same exponents as you and found the bad work that you have turned in. There have been several (IIRC) where you tried to self verify and had mismatches, ( again if memory serves, at least one of those was a PRP.) My error rate since 2009 is under 0.2%.

xilman 2023-06-27 20:13

[QUOTE=chalsall;633176]If I may... Few appreciate the importance of curators.

I have known people who have PhDs who became curators, documenting others' work for future researchers.

It's a thankless job.[/QUOTE]I worked with several curators with doctorates during my time with FlyBase. They did receive thanks from those who appreciated the valuable work they did.

An admirable career for Aspie pedants, amongst whose ranks I include myself.

kriesel 2023-06-27 21:07

[QUOTE=Uncwilly;633184]you buy used equipment and run into errors[/QUOTE]Actually a mix of new and used. And I may be running a larger than average-user proportion of larger exponents or longer runtimes. Part of the problem might be that I have too much [URL="https://mersenneforum.org/showpost.php?p=631511&postcount=2"]Dell[/URL] [URL="https://mersenneforum.org/showpost.php?p=612821&postcount=13"]hardware[/URL]. Or the wrong model numbers, or built on the wrong day by hungover line workers? Or high ambient temperatures sometimes. Who made your reliable hardware? My HP hardware seems more reliable.

Uncwilly 2023-06-27 21:33

[QUOTE=kriesel;633192]Who made your reliable hardware?[/QUOTE]"[I]Dude, I have (a) Dell.[/I]"
Several actually

Andrew Usher 2023-06-28 12:45

I can't help thinking Kriesel's use of GPUs probably contributes to his error rate; I doubt that with CPUs is out of line with the exponents he tests, but most of his bad results come from gpuowl (easily identified by its zero shift).


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