Prime95 version 29.6/29.7/29.8

[pepi37]

Originally Posted by Prime95

I believe LLR does not set affinity. So, the OS is in charge of placing the 3 threads amongst the 6 cores.

Prime95 uses hwloc to assign affinities. I think there is a way to tell prime95 to assign threads to any core like LLR -- poke around in undoc.txt or the worker windows dialog box.

Yes ,that is surprising why LLR give better results then Prime95. Prime 95 set coresm uses hwloc , and many other stuff that LLR doesnot do, and still LLR produce better results
Also I try trick with section on worker

[Worker #1]
Affinity=0,1,2


[Worker #2]
Affinity=3,4,5

Prime 95 assign cores as requested, but that doesnot change anything: after two hours of computing difference is already 5% between workers.

Originally Posted by Prime95

BTW, what is the total thoughput of LLR and prim95? If the throughput is the same prime95's affinity tricks have merely concentrated all the OS overhead into one worker wheras LLR has spread it over both workers.

It is obvious that total thoughput will be on LLR side, since in Prime95 case one worker is always slower, compared to LLR. So in 10-15 days I lost few processed candidates when do same job on Prime 95 compared to LLR

[VBCurtis]

Originally Posted by pepi37

It is obvious that total thoughput will be on LLR side, since in Prime95 case one worker is always slower, compared to LLR. So in 10-15 days I lost few processed candidates when do same job on Prime 95 compared to LLR

This is not at all obvious. In fact, I think it's unlikely.

[pepi37]

Originally Posted by VBCurtis

This is not at all obvious. In fact, I think it's unlikely.

OK let's it in simple words
With LLR I make 20 workinits,and in same time less then 20 if I do it with Prime 95. If you don't believe me it is easy to check.

[VBCurtis]

Well, then use LLR. Prime95's affinity settings/options are more advanced than LLR's, as George explained to you. Seems those settings stand in your way on this particular use case. I wouldn't choose P95 to run those tests anyway, since LLR is capable of proving a prime but P95 is prp-only for that form.

[pepi37]

Originally Posted by VBCurtis

Well, then use LLR. Prime95's affinity settings/options are more advanced than LLR's, as George explained to you. Seems those settings stand in your way on this particular use case. I wouldn't choose P95 to run those tests anyway, since LLR is capable of proving a prime but P95 is prp-only for that form.

With all respect you go out of theme. It is not relevant to use or not Prime95. Question is why is LLR better in this part then Prime95 regardless fact Prime95 has advanced core setting.

[James Heinrich]

Originally Posted by pepi37

With LLR I make 20 workinits,and in same time less then 20 if I do it with Prime 95.
If you don't believe me it is easy to check.

Perhaps you could make the effort to run the definitive test, since you're most concerned by it: Run a small set, say 4 exponents, through LLR, measure the exact real time it took to run those exponents. The run those exact same exponents again through Prime95, perhaps even two runs (one with two instances, one with two workers), again measuring the exact amount of time needed to complete all 4 exponents. Then you'll have some concrete numbers to posit your argument with.

Another test you could try would be to run one Prime95 instance with two workers, but only 2-threaded, explicitly assigned to cores 2,3 and 4,5 and leave cores 0,1 free for whatever Windows wants to do with them, and then see how the runtime compares between the two workers.

[pepi37]

Originally Posted by James Heinrich

Perhaps you could make the effort to run the definitive test, since you're most concerned by it: Run a small set, say 4 exponents, through LLR, measure the exact real time it took to run those exponents. The run those exact same exponents again through Prime95, perhaps even two runs (one with two instances, one with two workers), again measuring the exact amount of time needed to complete all 4 exponents. Then you'll have some concrete numbers to posit your argument with.

Another test you could try would be to run one Prime95 instance with two workers, but only 2-threaded, explicitly assigned to cores 2,3 and 4,5 and leave cores 0,1 free for whatever Windows wants to do with them, and then see how the runtime compares between the two workers.

I already do that, when I compare time with LLR. Time in LLR was near exact ones, and times in Prime 95 was like I post on picture.


https://www.dropbox.com/s/ueaucuktuym82jj/0025.jpg?dl=0


So look on this picture I have nothing to hide. Both workers start at 22:12:28
First worker done first result at 01:15 and second worker done it at 00:50. So difference is in this point is already 25 MINUTES!!!!!
What else you need ?
You can also see that after some time first worker make about 2.5 workunits , and second make above 3 workunits ( percentage in worker windows)
If I run it with LLR difference will be minute or two, but not 25 minutes!
Again ,this is real test, from real sequence, and you can repeat it on your computers.

[kriesel]

Very occasionally that error message appears in a prime95 results.txt. For example,

[Sun Apr 12 19:20:22 2020]
 Error writing intermediate file: p315690521

It's not an issue of enough disk space available. I'm finding these on every system I check, beginning at dates ranging over about 2 years, with the earliest found so far corresponding to V29.4. New or old hardware does not seem to matter.

What might cause that error?
Suggested solutions?

[kruoli]

On Windows 10 64 bit, I tried increasing priority of Prime95. It froze and crashed without further (immediately visible) information. In the event log there were two entries.

TL;DR: Windows thinks Prime95 wanted to access the file "" but failed to do so. In fact, the program was run from a network resource. It was running fine for days. Only when I changed priority, it crashed. That could happen if the file handle of prime.txt or local.txt are kept open for days and those files never get closed until the program exits. Writing results, re-reading worktodo.txt and doing backup files is no problem, because they should always have fresh file handles.

Unabbreviated event log, German (translation below):

Name der fehlerhaften Anwendung: prime95.exe, Version: 29.8.1.0, Zeitstempel: 0x5d59a427
Name des fehlerhaften Moduls: ntdll.dll, Version: 10.0.17763.1158, Zeitstempel: 0x54d5d94b
Ausnahmecode: 0xc0000006
Fehleroffset: 0x0000000000006aa8
ID des fehlerhaften Prozesses: 0x830
Startzeit der fehlerhaften Anwendung: 0x01d61f14458305b1
Pfad der fehlerhaften Anwendung: B:\Prime95\29.8b6\prime95.exe
Pfad des fehlerhaften Moduls: C:\WINDOWS\SYSTEM32\ntdll.dll
Berichtskennung: cac8b7b7-e3c7-47b0-93e5-e118bd66acf5
Vollständiger Name des fehlerhaften Pakets: 
Anwendungs-ID, die relativ zum fehlerhaften Paket ist: 

Aus einem der folgenden Gründe kann Windows nicht auf die Datei "" zugreifen: Es besteht ein Problem mit der Netzwerkverbindung, dem Datenträger mit der gespeicherten Datei bzw. den auf dem Computer installierten Speichertreibern, oder der Datenträger fehlt. Das Programm PRIME95 Application wurde von Windows wegen dieses Fehlers geschlossen.

Programm: PRIME95 Application
Datei: 

Der Fehlerwert ist im Abschnitt "Zusätzliche Dateien" aufgelistet.
User action
1. Öffnen Sie die Datei erneut. Diese Situation ist eventuell ein temporäres Problem, das selbstständig behoben wird, wenn das Programm erneut ausgeführt wird.
2. Wenn Sie weiterhin nicht auf die Datei zugreifen können und
	- diese sich im Netzwerk befindet,  dann sollte der Netzwerkadministrator sicherstellen, dass kein Netzwerkproblem besteht und dass eine Verbindung mit dem Server hergestellt werden kann.
	- diese sich auf einem Wechseldatenträger, wie z. B. einer Diskette oder einer CD, befindet, überprüfen Sie, ob der Datenträger richtig in den Computer eingelegt ist.
3. Überprüfen und reparieren Sie das Dateisystem, indem Sie CHKDSK ausführen. Klicken Sie dazu im Startmenü auf "Ausführen", geben Sie CMD ein, und klicken Sie auf "OK". Geben Sie an der Eingabeaufforderung CHKDSK /F ein, und drücken Sie die EINGABETASTE.
4. Stellen Sie die Datei von einer Sicherungskopie wieder her, wenn das Problem weiterhin besteht.
5. Überprüfen Sie, ob andere Dateien auf demselben Datenträger geöffnet werden können. Falls dies nicht möglich ist, ist der Datenträger eventuell beschädigt.  Wenden Sie sich an den Administrator oder den Hersteller der Computerhardware, um weitere Unterstützung zu erhalten, wenn es sich um eine Festplatte handelt.

Zusätzliche Daten
Fehlerwert: C00000C4
Datenträgertyp: 0

Attempted translation:

Name of the faulty application: prime95.exe, Version: 29.8.1.0, time code: 0x5d59a427
Name of the faulty module: ntdll.dll, Version: 10.0.17763.1158, time code: 0x54d5d94b
Error code: 0xc0000006
Error offset: 0x0000000000006aa8
ID of the faulty process: 0x830
Process start time: 0x01d61f14458305b1
Path of application: B:\Prime95\29.8b6\prime95.exe
Path of module: C:\WINDOWS\SYSTEM32\ntdll.dll
ID of the error message: cac8b7b7-e3c7-47b0-93e5-e118bd66acf5
Full name of the faulty package: 
Application ID relative to the faulty package: 

Windows could not access the file "" because one of the following reasons: There is a problem with the network connection, the hard disk with the file on it or the hard disk drivers; maybe a hard disk is missing. Because of this error, Windows force-closed the faulty application PRIME95 Application.

Program: PRIME95 Application
File: 

The error code is listed under "additional data".
User action
1. Reopen the file. May the error is temporary that gets fixed by itself, if the program is restarted.
2. If you keep getting errors accessing the file, please make sure
	- the file exists in the network, in that case the network administrator should assert, that there are no problems in the network infrastructure and the server is accessible.
	- the file exists on a removable device like a floppy, a CD or a thumb drive and make sure this drive is inserted into the computer correctly.
3. Check and repair the file system with CHKDSK /F.
4. Recover the file from a backup, if the error keeps happening.
5. Check if other files can be accessed on the same drive. Get help from the manufacturer if the drive is a hard disk.

Additional data
Error code: C00000C4
Volume type: 0

[garo]

There is no real reason to increase priority of Prime95 on windows. It looks like you raised the priority to the point that there was starvation.

[pepi37]

Originally Posted by kriesel

Very occasionally that error message appears in a prime95 results.txt. For example,

[Sun Apr 12 19:20:22 2020]
 Error writing intermediate file: p315690521

It's not an issue of enough disk space available. I'm finding these on every system I check, beginning at dates ranging over about 2 years, with the earliest found so far corresponding to V29.4. New or old hardware does not seem to matter.

What might cause that error?
Suggested solutions?

I have similar error in next condition: if you have two workers and both work on candidate with same exponent, then you will get similar error. I suggest that intermediate file got different name scheme so this error will not heapen again