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11) Message boards : Wieferich and Wall-Sun-Sun Prime Search : Any idea on WU times CPU vs. GPU? (Message 151465)
Posted 34 days ago by Profile Michael GoetzProject donor
Job cache is too small for this project. I am using an RTX 3090 FE GPU and each work unit takes about 4 minutes and 45 seconds to complete. Ever thought about greatly increasing the job cash for us high end GPU owners?


What exactly do you mean by "job cache"? Most of the queue and buffer controls that affect job flow are actually set by the user rather than by the admins.

If your computer isn't requesting work, that's a setting on your side. You may need to look at the messages in your BOINC log to see whether or not your computer is requesting work when it contacts the server.

If it is requesting work and you're not getting any, unless you're trying to grab an ungodly number of tasks (which is a terrible strategy and you shouldn't be doing that), then the problem is likely that you have run out of wingmen and all the available tasks are from workunits where you've already run a task, and are thus ineligible to get another task. If this is the problem, there's little that can be done about it other than convincing other people to run WW or to diversify your task selection.
12) Message boards : Problems and Help : Not first in PPS-MEGA? (Message 151417)
Posted 39 days ago by Profile Michael GoetzProject donor
I see. But why does the task get abandoned and later recovered?


They are marked as abandoned because the server thinks the host computer is no longer attached to PrimeGrid. Usually this happens because the host changed ID numbers or more than one host is using the same name or ID number. I can't tell you exactly what is happening on your computers because the problem is on your computers where we don't have visibility.

The "recovered" part is easy to understand, however. Jim wrote a program that periodically scans the server for tasks that are in an error state but actually do have valid result files. WHen it finds one, it changes the state to "pending validation" to give you an opportunity to get credit. Normally, BOINC would just discard these tasks.
13) Message boards : Problems and Help : Not first in PPS-MEGA? (Message 151397)
Posted 40 days ago by Profile Michael GoetzProject donor
Also, for the task above, it seems like I reported earlier (5:36 UTC) than my opponent (5:49 UTC). Why was the opponent given the 1st?


The recovery of your task most likely happened after the other task was returned and marked as the canonical (aka "1st") task.

Because the other task was completed and marked as first before the server's cleanup process found and "unabandoned" your task.
14) Message boards : Number crunching : All tasks are aborted (Message 151301)
Posted 49 days ago by Profile Michael GoetzProject donor
Hello,

Just of curiosity, I checked recent CW task I crunched and found out that the host below keeps aborting all WUs it gets.

https://www.primegrid.com/show_host_detail.php?hostid=1084645


Why is that?[/code]


LLR2 will not run on windows XP.


This is true, however, it's not the reason that host is aborting those tasks.

If a Windows XP gets an LLR2 task, it will ERROR; it will *not* ABORT.

This host is aborting tasks. They're not erroring out.

Also, it's aborting SGS tasks too, and these are the old LLR, not LLR2, and should run just fine on that host.

I do not know if this is the same host that we discussed recently on Discord, but if it's a different host it's exhibiting the exact same behavior. While it's impossible to know for certain what the actual cause is, the most likely reason that fits the known facts is that the computer's clock is set incorrectly with a time in the future.

As soon as BOINC downloads a task, because the clock is set wrong, it thinks the task is already past its deadline. BOINC automatically aborts *unstarted* tasks that are past their deadline. Every task is therefore immediately aborted and returned to the server, which dutifully sends more tasks to the host. This continues until a daily limit is reached.

It doesn't hurt any other users, and it doesn't hurt the server, so you can safely ignore this host.
15) Message boards : Number crunching : Once in a Blue Moon Challenge (Message 151201)
Posted 58 days ago by Profile Michael GoetzProject donor
Why is the abortion-rate that high?
I mean, i too aborted around 10 %, to "realign" the WUs with some DC-tasks, but that high a percentage?
Any ideas?

There are many scenarios in which you download more tasks than you actually want to run and abort some of them – maybe by some logic. Some of them were outlined by others above, but I'ld like to point out one more.

There's a bug in BOINC where – if you don't have any tasks for some subproject in your client_state.xml or whatever and you start running that subproject, it will download one task per each core (as if you were going to run one task per core), independent of the settings of how many cores per task you've set for the subproject. So it's very possible to get way too many tasks downloaded at the start of the challenge like this and abort most of them.

Maybe this was fixed or alleviated by the changes with how you can set multi-threading from the server side preferences now, I wouldn't know for sure (haven't crunched in... years now).


Very likely the high abort rate is from DC task hunting. With the long running llrPSP tasks,
you may have a large amount of time left after running your last long task that will finish
before the challenge ends. So you can run DC tasks to use the remaining challenge time.
You do this by downloading 10 days of tasks, aborting all the long tasks, and keeping the
DC tasks to do after your last long task finishes


While that's indeed a plausible and reasonable explanation, the actual explanation is that it's mostly due to a single broken computer -- most likely with its system date set in the future -- that is continuously and automatically aborting all tasks as soon as they're received. It's certainly not intentional.


If you go to go to the Challenge leaderboard and look for users that have 5 times or more
tasks than their neighbors, they're probably DC task hunting, and aborting a lot of tasks.


It's certainly possible that people are doing this, but they're not the cause of the large number of aborted tasks. If this is happening, it's only causing a smaller portion of the aborts. By a significant margin, the largest source of the aborts is a single malfunctioning computer.

What you're suggesting isn't at all unreasonable. I suspected the same thing, which is part of the reason I looked into what was happening. But this wasn't, in fact, the cause of the aborts.
16) Message boards : Number crunching : Once in a Blue Moon Challenge (Message 151196)
Posted 58 days ago by Profile Michael GoetzProject donor
Why is the abortion-rate that high?
I mean, i too aborted around 10 %, to "realign" the WUs with some DC-tasks, but that high a percentage?
Any ideas?

There are many scenarios in which you download more tasks than you actually want to run and abort some of them – maybe by some logic. Some of them were outlined by others above, but I'ld like to point out one more.

There's a bug in BOINC where – if you don't have any tasks for some subproject in your client_state.xml or whatever and you start running that subproject, it will download one task per each core (as if you were going to run one task per core), independent of the settings of how many cores per task you've set for the subproject. So it's very possible to get way too many tasks downloaded at the start of the challenge like this and abort most of them.

Maybe this was fixed or alleviated by the changes with how you can set multi-threading from the server side preferences now, I wouldn't know for sure (haven't crunched in... years now).


Very likely the high abort rate is from DC task hunting. With the long running llrPSP tasks,
you may have a large amount of time left after running your last long task that will finish
before the challenge ends. So you can run DC tasks to use the remaining challenge time.
You do this by downloading 10 days of tasks, aborting all the long tasks, and keeping the
DC tasks to do after your last long task finishes


While that's indeed a plausible and reasonable explanation, the actual explanation is that it's mostly due to a single broken computer -- most likely with its system date set in the future -- that is continuously and automatically aborting all tasks as soon as they're received. It's certainly not intentional.
17) Message boards : Number crunching : Once in a Blue Moon Challenge (Message 151191)
Posted 59 days ago by Profile Michael GoetzProject donor
(...)
This computer probably isn't even set up to run the challenge as it's doing this on many of the sub-projects. It's doing more PSP than others because the server is set to favor challenge tasks (this improves performance.)

So there you have it. The big number of aborts is mostly due to a single broken computer.


Interesting - and good explanation which with lacking insight i could not deduce.

by the way: I changed my E5-2690 out and my E5-2670 v3 in, now 2 tasks were started with AVX and are completed with FMA3, is this a game breaker? Should i abort the tasks, or would they come out just fine?

(since nobody asked - i swapped the ssd, since the CPUs won't fit in the same board. ;) )


2 x 2 = 4 no matter whether you use AVX or FMA3 to do the multiply, so you're fine. The transform is used to get from step N to step N+1, but the result is the same no matter the method you use to do the math. The checkpoints are done between completed steps.

You can also change the number of threads between saves, although it's a bit tricky to get both BOINC and LLR to recognize the change.

That being said, completing the calculation correctly isn't the only thing you need to worry about. if you switched the CPU (and the motherboard too???) the BOINC server may (or may not) decide this is a brand new host. If it does, it will reject the tasks when they're returned. I suggest hitting the "Update" button, and see A) if there's any error messages in the log, and B) whether you see the computer with a new host ID on the PrimeGrid website.

If it created a new host, then yes, abort the tasks. If it didn't, it should be ok to continue running them.
18) Message boards : Number crunching : Once in a Blue Moon Challenge (Message 151186)
Posted 59 days ago by Profile Michael GoetzProject donor
Why is the abortion-rate that high?
I mean, i too aborted around 10 %, to "realign" the WUs with some DC-tasks, but that high a percentage?
Any ideas?


Well, you got me interested, so I took a look.

There's a few people with a *LOT* of aborted tasks. I dug deeper and... it's not some evil strategy to dominate the world. It's not actually anything interesting at all. It's mostly a single computer which is instantly aborting *all* of its tasks. When it only takes a few seconds per task, a single computer can break many thousands per day.

My guess is the clock on the computer is set wrong; specifically, it's set to sometime in the future beyond any of the tasks' deadlines. When this happens (and we've seen this before), as soon as BOINC downloads a tasks, it realizes (erroneously) that the tasks are past their deadline, and have not yet started to run. BOINC then immediately aborts the task. Rinse and repeat, ad infinitum.

This computer probably isn't even set up to run the challenge as it's doing this on many of the sub-projects. It's doing more PSP than others because the server is set to favor challenge tasks (this improves performance.)

So there you have it. The big number of aborts is mostly due to a single broken computer.
19) Message boards : Number crunching : Once in a Blue Moon Challenge (Message 151172)
Posted 60 days ago by Profile Michael GoetzProject donor
It would be very nice if there was a PG project switch to send ONLY DC tasks for LLR subprojects. Without such a switch, I will be forced to download a 10 day queue of PSP tasks, and then abort any that I can't finish in the time remaining.

If was discussed few times already and it's just not possible. To generate stable flow of DC tasks for just one computer, 64 slave computers working on main tasks will be required.


A DC ONLY switch ...


Let me help out with the word you're having trouble with...


impossible [ im-pos-uh-buhl ]

adjective

  1. not possible; unable to be, exist, happen, etc.
  2. unable to be done, performed, effected, etc.:
    an impossible assignment.
  3. incapable of being true, as a rumor.
  4. not to be done, endured, etc., with any degree of reason or propriety:
    an impossible situation.
  5. utterly impracticable:
    an impossible plan.
  6. hopelessly unsuitable, difficult, or objectionable.



(From dictionary.com.)

20) Message boards : Cullen/Woodall prime search : Future CW-sieve. (Message 150941)
Posted 83 days ago by Profile Michael GoetzProject donor
For base 2, the NVIDIA sieve is faster, but that sieve does not support other bases.


To be clear, there's no need for additional *G*CW sieving at this point (or anywhere in the near future.) The interest is only for base 2 sieving.


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