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drummers-lowrise
11) Message boards : Number crunching : Tour de Primes 2020 (Message 137555)
Posted 177 days ago by Profile composite
The server could be set to send double-checks, say, 1 day later. Maybe 1 hour for tests faster than PPS? Then we could all abandon this multithreading stuff and we'd probably find more primes overall.

This would not work because a user has no choice to receive only unchecked numbers. What does it matter whether we are processing yesterday's leftovers instead of today's?

Also which numbers are prime does not change by finding them faster, so there's no opportunity for finding "more" primes. All that changes is how quickly they are found. I think you mean that it is more likely that "we" will find them.

Being the devil's advocate... what if "someone" found them already and we just don't know it? We could just stop all this prime search nonsense if "someone" just dumped them on us. If you had just one choice, would you rather ask of an intelligent extraterrestrial for the complete list of primes up to some arbitrary N, or for the cure for an arbitrary disease afflicting humans?
12) Message boards : Number crunching : Tour de Primes 2020 (Message 137547)
Posted 177 days ago by Profile composite
Nice display of personal stats.
Would it make sense for this table to be public info on account pages?

And a request for a global page showing a table of percentiles-vs-first percentage for each subproject, to provide context for the personal table.


Maybe I'm confused here... but wouldn't the overall average ALWAYS be 50%? Someone gets it in first, someone second. Obviously when you break it down by account, the person with the fastest hardware gets more firsts, but it's still going to total 50%.

Percentile is usually an S-curve: a sloped section with a long near-horizontal tail at both ends. Are you saying that the inflection point of that curve is always at 50%? I disagree. In the extreme case, one user with a set of superfast CPUs can get up to 50% of all the tasks in a subproject (because of DC requirement) yet be the only person who has a first percentage > 5%. In that case it's useless for her to try to raise that first percentage to 10%.

EDIT:
Hmmm. In the extreme case cited, with 1000 users working on a subproject and rounding first-percentage to the nearest half percent, the second column would consist entirely of 0% because one person hogging all the firsts is just 0.1% of all users, and the other 999 users are all double-checkers.
13) Message boards : Number crunching : Tour de Primes 2020 (Message 137542)
Posted 177 days ago by Profile composite
Nice display of personal stats.
Would it make sense for this table to be public info on account pages?

And a request for a global page showing a table of percentiles-vs-first percentage for each subproject, to provide context for the personal table.
The first column of each table lists first percentage (say in 5% increments, up to the maximum first percentage),
and the second column shows the percent of accounts (having a first percentage > 0 in that subproject)
whose first percentage exceeds the value in the first column.
Then 100% of users exceed 0% (so don't bother computing exceedance for 0%),
and (for example) if the maximum first percentage is 87%, then compute and display exceedance up to 85%.
It would be reasonable to update this page at a some interval, say daily or hourly, to reduce load on database server.
14) Message boards : Proth Prime Search : Naive question about 24M-digits PPS numbers (Message 137317)
Posted 179 days ago by Profile composite
Is it possible to compute a sort of IBDWT with integers and a fast deterministic Proth test? ... I haven't found it.

How far does this all integer IBDWT (GitHub) get you toward that goal?
15) Message boards : Number crunching : Tour de Primes 2020 (Message 137316)
Posted 179 days ago by Profile composite
Can you be your own wing man if you have several computers?

... By design, this is prohibited, but there's a race condition where it can happen anyway. ...

Dijkstra famously published in 1965 the solution to race conditions in software.
But every single software designer using concurrency has to be aware of the solution, by reading about it, by being shown the solution, or by reinventing it.
16) Message boards : Problems and Help : random error on PPSE after ~15 sec on linux (Message 136901)
Posted 186 days ago by Profile composite

execl failed once: Text file busy

"Text file busy" happens when a process tries to overwrite or delete a program file while another process is running it. I get that at work when I am deploying a new version of software but another user is running it. Renaming the running executable file before writing the new version gets around that.

Could it be that you have 2 BOINC clients running? Rebooting should fix that.

On the subject of rebooting, if you haven't updated your Linux kernel and rebooted since September, I suggest that it's high time to do it. Fedora especially has multiple kernel updates each year to address security issues and fix bugs.
17) Message boards : Number crunching : 2020 Challenge Schedule! (tentative) (Message 136130)
Posted 215 days ago by Profile composite
Too late now for this idea (this year anyway).
To find the First Prime Of The Year (UTC): FPOTY.
It's a New Year's Day "baby" prime challenge.

EDIT: or maybe not too late. None has been reported yet, this year.
18) Message boards : Number crunching : New Hardware (Message 135351)
Posted 241 days ago by Profile composite
On a trip to Geneva visiting friends, I visited CERN's science display/museum. I was standing beside a big hunk of mainframe and telling them how I used these in the old days, then turned around and to my astonishment on a tabletop under a plexiglas case Time Berner-Lee's Nextcube was right there, with a note saying this was the world's first web server.
19) Message boards : Number crunching : New Hardware (Message 135339)
Posted 241 days ago by Profile composite
EDIT: went looking for thermal paste and found two boxes of five and a quarter inch floppies.... lol.

It's probably behind that stack of eight inch floppies.


lol. they're 5.25 for my Apple //e! 8 inch.... I'm not that old!

But I am, lol. Maybe the bits have evaporated by now.
20) Message boards : Number crunching : New Hardware (Message 135319)
Posted 242 days ago by Profile composite
EDIT: went looking for thermal paste and found two boxes of five and a quarter inch floppies.... lol.

It's probably behind that stack of eight inch floppies.


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